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ICSE Solutions for Class 8 Geography Voyage – Asia: Climate and Natural Vegetation

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ICSE Solutions for Class 8 Geography Voyage – Asia: Climate and Natural Vegetation

ICSE SolutionsSelina ICSE SolutionsML Aggarwal Solutions

ICSE Solutions Class 8 GeographyHistory & CivicsBiologyChemistryPhysicsMaths

Exercises

A. Fill in the blanks

  1. A few regions of South-west Asia receive winter rainfall from the temperate cyclones that originate over the Mediterranean Sea. (tropical cyclones, temperate cyclones, north-east winds, south-east winds)
  2. The Mediterranean climate is ideally suited growing citrus fruits, (equatorial, warm temperate east coast, Mediterranean, tropical monsoon).
  3. The tropical rain forests of Asia are dense and impenetrable, (steppes, mangrove forests, monsoon forests, tropical rain forests)
  4. About one-third of the land area of Asia is covered with forest.
  5.  Thermal electricity is produced by burning coal and petroleum.

B. Match the following

ICSE Solutions for Class 8 Geography Voyage Chapter 8 Asia Climate and Natural Vegetation 1
Answer:

ICSE Solutions for Class 8 Geography Voyage Chapter 8 Asia Climate and Natural Vegetation 2

C. Answer the following questions in brief

Question 1.
When does most of Asia receive maximum rainfall ? Give a reason for your answer.
Answer:
Most of the Asia receives maximum rainfall in the months of April, May and June. In summers, most of Asia has an average temperature of about 32°C. The hot air over the land rises and creates an area of low pressure. There is high pressure in the surrounding seas and oceans. So there is movement of warm moisture-laden onshore winds which are called monsoons. These winds cause heavy rainfall.

Question 2.
Name any two countries that experience Mediterranean climate.
Answer:
Syria, Turkey, Lebanon and Israel experience Mediterranean climate.

Question 3.
Explain how the climate of the cold temperate regions of Asia has affected the :

  1. Vegetation
  2. Wildlife

Answer:

  1. Vegetation of the cold temperate regions of Asia — These regions experience long severe winters with heavy snowfall and very short, cool summers with light rainfall. So the natural vegetation has adapted very well to the climate. The evergreen softwood trees of the region are conical in shape and have needle-like leaves. They are called coniferous trees as they have cones in which they bear their seeds. The common tree species are pine, fir, spruce, larch and cedar. The forests are also called as taiga.
  2. Wildlife — Several small to medium sized animals such as the fox, sable, bear, mink, lynx and squirrel are found here which have fur over their bodies to protect them from cold weather.

Question 4.
Name some wildlife species found in the taiga region, the tundra region, and the tropical deciduous forests of Asia..
Answer:
Wildlife species found in the taiga region are fox, sable, bear, mink, lynx and squirrel. Wildlife species found in the tundra region of Asia are polar bears, reindeer, foxes, seals and walruses.
Wildlife species found in the tropical deciduous forests of Asia are rhinoceros, elephants, bears, deer, apes, lions, tigers, leopards, etc.

Question 5.
Trees cannot grow of survive in the regions beyond the Arctic Circle in Asia. Why ?
Answer:
Trees or forests cannot grow or survive in the regions beyond the Arctic Circle in Asia because this region has long severe winters and the frozen subsoil which do not permit the growth of trees and this region is, therefore, devoid of forests.

D. Answer the following questions in one or two paragraphs

Question 1.
Identify the main factors that affect the climate of Asia. Explain any two of them.
Answer:
The Main factors that affect the climate of Asia are :

  1. Size and latitudinal extent — Asia is the largest continent with a large east-west extent. Also, it stretches across the torrid, temperate and frigid heat zones of the earth.
  2. Distance from the sea — Many parts of Asia are far away from the maritime influence of the seas and oceans and experience extreme conditions and continental climate. Places closer to the’Coasts enjoy equable or maritime climate.
  3. Relief features — like mountain ranges of Asia extend in the east-west direction and form barriers to the moisture laden winds and the cold winds.
  4. Wind — Moisture bearing winds from the south and cold winds of the north affect the climate of the places.
  5. Ocean Currents — The cold Oya Siwo and the warm Kuro Siwo ocean currents affect the temperatures of the coastal regions of Japan.

Question 2.
Describe the climatic conditions in Asia from October to March.
Answer:
From October to March, Asia experiences winter season as the northern hemisphere receives the slanting rays of the sun because of the tilt of the earth’s axis. The temperature falls to 0°C and even below freezing point in many parts of the northern Asia. The air over the land is cold and heavy and sinks causing high pressure. The surrounding oceans and seas ! have higher temperature and lower pressure so the cold air
moves from land (high pressure) to sea (low pressure). These winds are dry and hence most of the Asia receives no winter rainfall except South-East Asia, Japan, South-Eastern India i and parts of Sri Lanka, where the same winds cross the seas
and pick up moisture. A few regions of South-West Asia receive winter rainfall from the temperate cyclones that originate over the Mediterranean Sea.

Question 3.
Write about the Mediterranean climate experienced in Asia.
Answer:
The Mediterranean Climate in Asia is characterized by warm, dry summers and cool, wet winters.
Since these areas experience drought-like conditions in summer, the natural vegetation has adapted to the climate by developing long roots and spongy barks. The evergreen vegetation of oak, acacia, laurel, chestnut, walnut and olive trees is common. Orchards of citrus fruits such as lemons, and oranges, vineyards and farm grains have replaced the natural vegetation. In the absence of natural habitat, not much wildlife is found. Mostly domesticated animals such as donkeys, cattle and sheep are found.

Question 4.
Describe each of these forests :

  1. Tropical deciduous
  2. Equatorial rainforest.

Answer:

1. Tropical deciduous forests — They are found in tropical monsoon climate. These areas have hot wet summers with heavy rainfall and cool dry winters. Tropical deciduous forests are also called as monsoon forests. They have hardwood, broad-leaved trees which shed their leaves, in the dry season, usually in winter. Teak, Sal, shisham and mango are the common tree species. These thrive in regions of heavy rainfall. Grasses and thorny bushes grow in drier regions. Elephants, rhinoceros, bear, deer, apes, lion tiger, leopard, etc are some of the wildlife species found here.
Such forests are found in India, Pakistan, Bangladesh, Thailand, Myanmar, Vietnam, Laos, Cambodia and Southern China.

2. Equatorial rainforest — Such forests are found in equatorial climate where the temperatures are high of about 28-30°C and rainfall occurs all year round. Such climatic conditions have resulted in dense, hardwood forests with broad-leaved tree species such as mahogany, ebony, rosewood, cinchona, coconut and rubber. There are lianas, creepers and climbers, tall grass, ferns and bamboos that grow between the tall trees, which makes the forests dense and impenetrable. The forests are dark and gloomy as very little sunlight reaches the ground owing to the tall trees whose branches spread out, forming a canopy. Mostly arboreal or tree-dwelling animals such as monkey, apes and colourful birds are found. Reptiles such as lizards, snakes, crocodiles and insects are found in the swampy floors of the forests. Large animals such as elephants and wild cats are only found in the outskirts as the forest interior is too dense.
Such forests are found in countries located close to the equator like Malaysia, Indonesia, and Southern Philippines.

Question 5.
How has modernization changed the natural vegetation of the Mediterranean and steppe regions ?
Answer:

  • Mediterranean region — Due to modernization, most of the natural vegetation has been replaced by grain farms, orchards of citrus fruits such as lemons and oranges and vineyards.
  • Steppes region (Temperate Grassland) —Vast areas of grasslands have been converted into rich farmlands that grow wheat, barley and other food grains.

Question 6.
How are forests useful to the people of Asia?
Answer:
About one-third of the land area of Asia is covered with forest. Some of these forests provide hardwood, bamboo, sandalwood and camphor. They also provide other valuable forest products such as lac, resin, turpentine, honey, medicinal plants and herbs. Natural rubber is obtained from the latex of the rubber tree. The evergreen rainforest of the equatorial region and the monsoon forests of the tropical regions of Asia are the chief sources of these products.
Softwood forests yield softwood for making paper, pulp, newsprint, matchsticks and synthetic fibers such as rayon. These are obtained from trees such as birch, pine, cedar and fir, which grow in the taiga or coniferous forests region of northern Asia, especially Siberia.

Question 7.
Give an account of the mineral resources of Asia.
Answer:
Asia has vast deposits of different types of minerals such as iron ore (India, Malaysia, China, Russia, Japan, the Philippines, North Korea), coal (China, India, Kazakhstan, Russia), bauxite (India, Indonesia, Russia), and petroleum (Saudi Arabia, United Arab Emirates, Bahrain, Kuwait, Iran, Iraq, Malaysia, Indonesia, China, Russia).

E. Map study
On an outline map of Asia, mark the following:

  • area affected by the monsoons
  • regions of equatorial climate
  • regions of Mediterranean climate
  • areas under the steppes

Answer:
(a) Area affected by the monsoons

ICSE Solutions for Class 8 Geography Voyage Chapter 8 Asia Climate and Natural Vegetation 3
ICSE Solutions for Class 8 Geography Voyage Chapter 8 Asia Climate and Natural Vegetation 4

F. Picture study

Question 1.
Identify the animal seen in the photograph.
Answer:
Yak

Question 2.
In which climatic region of Asia can you find this animal ?
Answer:
Temperate or mid-latitude Desert region of Asia.

Extra Questions

Question 1.
Write a short note on summer conditions in Asia.
Answer:
From April to June, the sun rays fall directly over the northern hemisphere. In June, it shines overhead the Tropic of Cancer, so most of the continent of Asia, except the extreme northern parts beyond the Arctic Circle is warm with an average temperature of 32°C. Most of the Asia receives maximum rainfall in these months.

Question 2.
Why is Siberia so sparsely populated ?
Answer:
Siberia is sparsely populated as the climate here is very cold. Winters are long and severe with heavy snowfall which the summers are short and cool.

Question 3.
Write a short note on the tropical or hot desert climate and the natural vegetation and wildlife found there.
Answer:
Tropical or hot desert climate prevails in Arabia, Iran and the Thar desert in India and Pakistan. These regions experience very hot dry summers and very cold winters. The daily and annual ranges of temperature are very high and the areas receive less than 25 cm of rainfall annually.
As climatic conditions are harsh, vegetation is scarce and only thorny bushes, shrubs, cacti and clumps of dry grasses are found scattered in the region which is largely bare and devoid of vegetation. Date palms are found in the oases. Camels, horses, mules, gazelles, insects and lizards are some of the wildlife species found in the deserts.

Question 4.
What type of climate do China, Japan and Korea experience?
Answer:
China, Japan and Korea experiences warm temperate eastern margin or China type climate. It is similar to monsoon type except that the winters are colder. Snowfall occurs in winters while rainfall occurs in summer.

Question 5.
Which is the most common domesticated animal in Tibet ? What kind of climate is found in the Plateau of Tibet and the Gobi Desert ?
Answer:
Yak is the most common domesticated animal in Tibet. Temperate (or mid-latitude) desert climate is found in the Plateau of Tibet and the Gobi Desert. Very little rainfall, very cold winters with temperatures below the freezing point and very hot summers is found.

Question 6.
What increases the commercial value of forests in cool temperature eastern margin climate ?
Answer:
Oak, beech, maple and birch are the main trees and their occurrence in almost pure stands and predominance of only a handful of species greatly increase the commercial value of these forests.

Question 7.
List the major types of climate of Asia.
Answer:
The major types of climate of Asia are :

  1. Equatorial climate
  2. Tropical monsoon climate.
  3. Tropical or hot desert climate. .
  4. Warm temperate eastern margin or China type climate.
  5. Temperate or mid-latitude desert climate.
  6. Mediterranean climate
  7. Cool temperate eastern margin climate
  8. Temperate grassland or steppe climate
  9. Cold temperate or taiga climate
  10. Arctic or tundra climate.

Question 8.
What are the different types of vegetation found in varied climatic conditions of Asia ?
Answer:
The different types of vegetation in Asian climate include dense evergreen hardwood forests, tropical deciduous forest, thorny bushes, coarse short grasses, evergreen softwood trees and mosses and lichens.

9. Fill in the blanks.

  1. The areas away from the coasts experience continental (extreme), climate while places closer to the coasts experience maritime (equable) climate.
  2. World’s highest surface temperature of 71°C has been recorded in Dasht-eLut in Iran.
  3. Mawsynram in Meghalaya receives the heaviest rainfall in the world.
  4. Verkhoyansk in Russia is the coldest region in Asia with an average temperature of-51 °C. ’
  5. Most of the Asia receives no rainfall in winter.
  6. Convectional rainfall occurs almost daily around 4 o’ clock in equatorial climate region of Asia.
  7. Latex is the milky sap of rubber tree which is collected and used to make rubber for commercial purposes.
  8. The equatorial (tropical) rainforests are different from the rainforests of the Amazon and Zaire basins because of their nearness to the sea.
  9. India has tropical monsoon climate and tropical deciduous (monsoon) forests.
  10. Date palms are found in the Oases in hot deserts.
  11. The Gobi Desert stretches across large parts of Mongolia and China.
  12. Yak is one of the most commonly domesticated animals in the temperature desert regions of Asia.
  13. The two-humped Bactrian camel is a well-known animal of temperate grassland or steppe.
  14. The temperate grassland region of Central Asia is called steppe.
  15. The forests of the cold temperate regions, have coniferous trees with needle like leaves.
  16. The coniferous forests in cold temperate climate are called as Taiga.
  17. The treeless plains in the Arctic climate are called Tundra.

Map Skills
On a physical map of Asia, show the different types of climate and natural vegetation
Answer:

ICSE Solutions for Class 8 Geography Voyage Chapter 8 Asia Climate and Natural Vegetation 5

ICSE Solutions for Class 6 History and Civics – Rise of Kingdoms and Republics

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ICSE Solutions for Class 6 History and Civics – Rise of Kingdoms and Republics

ICSE SolutionsSelina ICSE SolutionsML Aggarwal Solutions

APlusTopper.com provides step by step solutions for ICSE Solutions for Class 6 History and Civics Chapter 7 Rise of Kingdoms and Republics. You can download the History and Civics ICSE Solutions for Class 6 with Free PDF download option. History and Civics for Class 6 ICSE Solutions all questions are solved and explained by expert teachers as per ICSE board guidelines.

ICSE Solutions Class 6 History & Civics Geography Biology Chemistry Physics Maths

Exercise

I. Fill in the blanks:

  1. More powerful territories in the 6th century were referred to as Mahajanapadas.
  2. In monarchy kingship was hereditary.
  3. Magadha emerged as the most powerful kingdom in North India in the sixth century BC.
  4. Alexander the Great invaded India in 326 BC.
  5. Porus impressed Alexander by his bravery and wisdom.
  6. A new school of art called Gandhara developed, as a result of Alexander’s invasion of India.

II. Match Column A with Column B:
ICSE Solutions for Class 6 History and Civics - Rise of Kingdoms and Republics 1
ICSE Solutions for Class 6 History and Civics - Rise of Kingdoms and Republics 2
Answer:
ICSE Solutions for Class 6 History and Civics - Rise of Kingdoms and Republics 3

III. Long Answer type Questions:

Question 1.
What were the main advantages that helped Magadha to emerge as the most powerful kingdom?
Answer:
With the help of following advantages Magadha emerged as the most powerful kingdom

  1. The presence of natural resources helped Magadha’s rise to power in the 6th century BC.
  2. Rich deposits of iron ore contributed to the making of effective iron weapons and agricultural tools.
  3. Due to strategic locations of both the capitals, Rajgriha (Rajgir) and Pataliputra, it was difficult for any rival to capture these cities.
  4. The Magadhan rulers had well-organised, efficient and powerful almies, which consisted of elephants, horses and chariots.
  5. The Magadhan territory being fertile, produced surplus food.
  6. The Magadhan rulers gained immensely from trade and commerce.
  7. The rivers like Ganga, Son, etc. provided waterways.

Question 2.
What policy did Bimbisara follow to extend his territories?
Answer:
Bimbisara extended his territories through conquests and marriages. He married the daughter of the king of Kosala and received the province of Kashi as dowry. The ruler of Kosala
thus became his friend. He also married the Lichchavi princess of Vaishali and thereby extended his friendship ties in this region. His third wife was the daughter of a chieftain of Punjab. Infact, Bimbisara was the first Indian king who brought a large part of Northern India under a unified political control.

IV. Short Answer type Questions:

  1. What is meant by the term Janapada ?
    Ans. The meaning of word ‘Janapada’ is the place where people put their pad or feet. The Janapada consisted of many villages and towns.
  2. Name the three most important Mahajanapadas.
    Ans. Kosala, Magadha, Avanti.
  3. Name the king who conquered Anga ?
    Ans. Bimbisara conquered Anga.
  4. Name the Magadhan king who killed his father ?
    Ans. Ajatashatru killed his father Bimbisara.
  5. Name a few towns that grew up in early days.
    Ans. Kasbi, Rajgriha, Vaishali, etc.
  6. Name the territories conquered by Bimbisara and Ajatashatru.
    Ans. Anga, Kosala, Vaishali, etc.

V. Give reasons why

  1. Bimbisara married princesses of his neighboring kingdoms.
    Ans. Bimbisara married princesses of his neighboring kingdoms to extend his territory.
  2. Deposits of iron in Magadha helped it become a powerful kingdom.
    Ans. Rich deposits of iron ore in Magadha contributed to the making of effective iron weapons and agricultural tools.

Textbook Keywords

  1. Janapadas: They were large states that grew in India as a result of wars and conquests. The word means the place where people place their feet.
  2. Mahajanapadas:  They were the powerful Janapadas. There were sixteen Mahajanapadas.
  3. Shakyas and Lichchhavis: They were the name of democratic republics ruled by representatives elected by the people.
  4. Gandhara School of Art: An Indo-Greek school of art that grew in India as a result of cultural contact with the Greeks.

Additional Questions

A. Fill in blanks.

  1. The pastoral Aryan tribes of the Early Vedic Period roamed about in search of new pastures. In the Later Vedic Period they began to cultivate the land.
  2. Large kingdoms were known as Janapadas and the more powerful among these were known as mahajanapadas.
  3. The four powerful kingdom in the Later Vedic Period were Vatsa, Avanti, Kosala and Magadha.
  4. The first important king of Magadha was Bimbisara.
  5. Alexander invaded India during the reign of the Magadha
  6. Dhana Nanda was overthrown by Chandragupta Maurya.
  7. Ambhi the ruler of Taxila, offered to help Alexander to defeat Porus.
  8. Alexander’s invasion led to the establishments of four different trade routes by land and sea.
  9. India’s cultural contact with the Greeks led to the development of a style of art known as the Gandhara School of Art.
  10. The power of the small states in north-western India was shattered by Alexander’s invasion.

B. Match the following.

ICSE Solutions for Class 6 History and Civics - Rise of Kingdoms and Republics 4
Answer:
ICSE Solutions for Class 6 History and Civics - Rise of Kingdoms and Republics 5
ICSE Solutions for Class 6 History and Civics - Rise of Kingdoms and Republics 6

C. Answer the following questions.

Question 1.
State the reasons for the emergence of the mahajanapadas.
Answer:
Surplus production, increased prosperity and the desire to expand further are the reasons for emergence of the mahajanapadas.

Question 2.
How many mahajanapadas are mentioned in the religious texts of the 6th century BCE?
Answer:
There are sixteen manhajanpadas are mentioned in the religious texts of the 6th century BCE.

Question 3.
How did the conquest of Anga benefit Magadha?
Answer:
The conquest of Anga brought the river port of Champa under his control of Magadha. The rich deposits of iron or found in this region contributed to the development of a strong and stable economy for Magadha.

Question 4.
Why was Alexander unable to conquer Magadha?
Answer:
Alexander was unable to Conquer Magadha because his army refused to advance any further. The army was war-weary and homesick and was not willing to face the powerful army of Magadha.

Question 5.
Mention briefly the effects of Alexander’s invasion.
Answer:
The effects of Alexander’s invasion were following.

  1. His invasion led to the establishment of four different trade routes by land and sea.
  2. Alexander’s historians have left dated records of his campaigns.
  3. The cultural contact with the Greeks led to the growth of the Indo-Greek School of Art known as Grandhara school of Art.

D. State whether the following are true of false.

  1. Magadha belonged to the Iron Age.
    False
  2. Alexander was the king of Rome.
    False
  3. The capital city of Magadha was Pataliputra.
    True
  4. Mahapadma Nanda was the last king of the Nanda dynasty.
    False
  5. Ambhi and Porus were allies.
    False

F. Picture study.
This is a painting of two important kings who became friends after war.
ICSE Solutions for Class 6 History and Civics - Rise of Kingdoms and Republics 7

Question 1.
Can you identify the two rulers in this painting ?
Answer:
Alexander and Porus are the two rulers in the painting.

Question 2.
Give an account of the earlier developments that led to this event.
Answer:
Porus was the ruler of the area lying between the rivers Jhelum and Chenab. Ambhi offered to help Alexander to defeat Porus. Porus fought heroically but was defeated. Fie was captured and brought before Alexandar who asked him how he would like to be treated. Porus replied ‘As one king should treat another king’ Alexandar was so impressed with reply that he set Pours free and they became friends.

Question 3.
Name the most powerful kingdom in India during this time. Which dynasty ruled this kingdom?
Answer:
Magadha was the most powerful kingdom in India during this time. Nanda dynasty ruled this kingdom.

Question 4.
Who overthrew the last ruler of this dynasty ? Name the empire established by him.
Answer:
Chandragupta Maurya overthrew the last ruler of Nanda dynasty. He established Maurya Empire.

ICSE Solutions for Class 7 History and Civics – Jahangir, Shah Jahan and Aurangzeb

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ICSE Solutions for Class 7 History and Civics – Jahangir, Shah Jahan and Aurangzeb

ICSE SolutionsSelina ICSE SolutionsML Aggarwal Solutions

APlusTopper.com provides step by step solutions for ICSE Solutions for Class 7 History and Civics. You can download the History and Civics ICSE Solutions for Class 7 with Free PDF download option. History and Civics for Class 7 ICSE Solutions all questions are solved and explained by expert teachers as per ICSE board guidelines.

ICSE Solutions Class 7 History & CivicsGeographyMathsPhysicsChemistryBiology

Important Words

  • The chain of justice is said to be a chain installed by Jahangir. It was made of pure gold with 60 bells attached to it, between the palace and the banks of the river Yamuna. Anyone could ring the bell and seek justice.
  • Engineer King is the name by which Shah Jahan is known, as his patronage of architecture is one of the most important characteristics of his reign.
  • Shahjahanabad was a new capital city build by Shah Jahan. Now, it is known as Old Delhi.

Time To Learn

I. Fill in the blanks:

  1. Taj Mahal, a symbol of love, shows a variety of cultural influences.
  2. Jahangir installed a chain of justice for the seekers of justice.
  3. The treaty of Purandhar was signed between Mughals and Rajput ruler Jain Singh.
  4. The original name of Nur Jahan was Mehrunnisa.
  5. Bijapur was annexed in AD 1686.
  6. Aurangzeb reimposed Jazia and pilgrimage tax.
  7. Guru Tegh Bahadur, ninth Sikh guru, was executed on Aurangzeb’s order.
  8. The Sikhs were organised into a military force called the Khalsa.

II. Match Column A with Columb B:
ICSE Solutions for Class 7 History and Civics - Jahangir, Shah Jahan and Aurangzeb 1
Answer:
ICSE Solutions for Class 7 History and Civics - Jahangir, Shah Jahan and Aurangzeb 2
ICSE Solutions for Class 7 History and Civics - Jahangir, Shah Jahan and Aurangzeb 3

III. State whether the following statements are True or False:

  1. Jahangir left the administration in the hands of his queen,Nur Jahan.
    True.
  2.  Nur Jahan’s influence was good and lasting for theMughal Empire.
    False.
  3. Shah Jahan had to fight for the throne.
    True.
  4. Shah Jahan married Mumtaz Mahal, in whose memory the built the Taj.
    True.
  5. Shah Jahan died in AD 1666, as a captive in the fort of Agra.
     True.
  6. Aurangzeb had friendly relation with the Rajputs and theMarathas.
     False.
  7. The Sikhs were hostile to the Mughal Emperor after the execution of the ninth Sikh guru.
    True.
  8. Aurangzeb died in 1707 in the Red Fort at Delhi.
    False.
  9. Aurangzeb reimposed .
    True.

IV. Answer the following questions briefly:

Question 1.
Jahangir is sometimes called a mixture of opposites. Discuss.
Answer:
Sometimes Jahangir was needlessly cruel and inflicted punishments disproportionate to the offence committed. For this combination of good qualities and bad qualities of his character some historian have rightly called him as ‘the mixture of opposites’.

Question 2.
How did Jahangir deal with the European traders? Name two travellers who visited Jahangir’s court.
Answer:
Jahangir was on good terms with the Portuguese traders. He gave them some trade concessions.Captain Hawkins and Sir Thomas Roe, visited Jahangir’s court.

Question 3.
The age of Shah Jahan is the Golden Age of Mughal rule. Do you agree? Give reasons for your answer.
Answer:
Yes, The age of Shah Jahan is the Golden Age of Mughal rule. The points describing are as follows:

  1. During the regin of Shah Jahan, there was undisturbed peace within the country. There were no foreign threats and Shah Jahan too devoted most of his time in maintaining peace and order in the country. Trade and commerce flourished bringing in lots of wealth. The land was fertile and revenue flowed into the treasury.
  2. Shah Jahan carried out many works of public welfare. Roads, canals, bridges, sarais, etc., were constructed for the welfare of the people. Similarly, during the famine and plague he did a lot to relieve the people of their sufferings.
  3. Shah Jahan had a natural love for magnificence, which was reflected in the buildings that he constructed. His reign is, in fact, called the Golden Age of the Mughal Architecture. One of the most important buildings constructed by him is the Taj Mahal, which was built in the memory of his beloved wife Mumtaz Mahal.

Question 4.
Describe the religious policy of Aurangzeb. What were its results?
Answer:
Aurangzeb’s religious policy had two aspects i.e:

  1. To promote the tenets of Islam and to ensure that the people led their lives accordingly.
  2. To adopt anti-Hindu measures.

The religious fanaticism of Aurangzeb overshadowed his virtues. His reversal of Akbar’s policy of religious toleration resulted in weakening the entire structure of the Mughal empire. It led to several conflicts and wars in different parts of the country.
These conflicts were:

  1. Conflict with the Jats
  2. Conflict with the Satnamos
  3. Conflict with the Sikhs
  4. Conflicts with the Rajput’s
  5. Conflict with the Marathas.

All these rebellions destroyed the peace of the empire, disrupted its economy, weakened the administrative structure, diminished its military strength, led to the failure of Aurangzeb to make any impact. Ultimately all these contributed to the downfall of the Mughal enterprise.

Question 5.
Who were the Sikhs? How did they emerge as a political power?
Answer:
Khalsa’s were the sikhs.
Open wars started between the Sikhs and the Mughals after Ninth Sikh Guru, Guru Tegh Bahadur was executed on Aurangzeb’s order. Aurangzeb and his successors had to face continous trouble from the sikhs. After Aurangzeb’s death, his successors failed to check the rising power of the Sikhs. The Sikhs gradually emerged as a political power.

Question 6.
Briefly describe aurangzeb’s clash with : (a) the Rajputs, (b) the Marathas, (c) the Sikhs.
Answer:
(a)
The Rajputs were not well treated by Aurangzeb. Raja Jai Singh and Raja Jaswant Singh were kept away from the court at Delhi. Raja Jai Singh was a loyal general but he was suspected and insulted after the escape of Shivaji.
(b)
Conflicts started between the Mughals and the Marathas over the conquest over the conquest of Bijapur.
(c)
The relations between the Sikhs and the Muslims were already strained because of Guru Arjan Dev’s execution at the hands of Jahangir for helping his rebel son. From then onwards, the Sikhs had become the enemies of the Mughals. Guru Gobind Singh, the tenth Guru and son of Guru Tegh Bahadur, continued the policy of his father. He organised the Open wars started between the Sikhs and the Mughals.

Question 7.
Why do you think Aurangzeb reimposed some taxes?
Answer:
Aurangzeb reimposed Jazia and pilgrimage tax because of his othodox relious policies.

Question 8.
Explain the factors responsible for the decline of the Mughal empire.
Answer:
The factors responsible for the decline of the Mughal empire are:

  1. Aurangzeb’s Faulty Policies: Aurangzeb followed an orthodox religious policy. He reimposed Jazia and pilgrimage tax. Thus, he antagonised not only the Hindus but also the Muslims. He also made enemies of communities like the Jats, Sikhs and the Marathas.
  2. Aurangzeb’s Deccan Policy: The conquests of Bijapur and Golconda made the empire too big to be administered efficiently. Moreover, Aurangzeb’s long stay in the Deccan (almost 25 years) neglected the administration of his empire in the North. His absence also helped the rise of the Maratha power.
  3. Weak Successors: Aurangzeb’s successors were incompetent and weak, and they could not suppress the revolts or control the nobles. They become too ambitious, and independent. Eventually, the governors of the Deccan, Awadh and Bengal declared themselves as independent rulers.
  4. Empty Treasury: Aurangzeb maintained a large standing army. But his long wars in the Deccan caused a big drain on the state treasury. Thus, after the death of Aurangzeb (AD 1707), the treasury became empty and the later Mughal rulers were unable to pay the soldiers and officers and meet their expenses.

V. Write a short note on 

Question 1.
Aurangzeb’s Deccan Campaigns
Answer:
Aurangzeb wanted to crush the growing powers of the Maratha’s. As these people were very strong and courageous and they also did not accept the over lordship of the ruler. This empire was also very vast and prosperous, so Aurangzeb wanted to have it under his control.

Question 2.
Abdali’s invasion on India
Answer:
Ahmad Shah Abdali invaded India several times between 1747 and 1767. He gave a crushing defeat to the Marathas in 1761 in the third Battle of Panipat. The Marathas could not regain their past power ever again.

Additional Questions
(Jahangir, Shah Jahan and Aurangzeb)

A. Fill in the blanks:

  1. Nur Jahan became the virtual ruler of the Mughal empire.
  2. During the final years of Jahangir’s reign, there was a power struggle between Nur Jahan and Shah Jahan.
  3. Shah Jahan’s reign is often referred to as the Golden Age of the Mughal empire.
  4. Aurangzeb spent the first half of his reign in the North and the second half in the Deccan.
  5. Aurangzeb spent the last twenty six years of his reign fighting against the Marathas and the Sultanates of Bijapur and Golconda.

B. Match the following:
ICSE Solutions for Class 7 History and Civics - Jahangir, Shah Jahan and Aurangzeb 4
ICSE Solutions for Class 7 History and Civics - Jahangir, Shah Jahan and Aurangzeb 5
Answer:
ICSE Solutions for Class 7 History and Civics - Jahangir, Shah Jahan and Aurangzeb 6

 

C. Choose the correct answer:

1. The foundations laid by Akbar/Babur/Humayun were so strong that Jahangir did not have any major problems maintaining the empire.
Ans. The foundations laid by Akbar were so strong that Jahangir did not have any major problems maintaining the empire.

2. Shah Jahan built the magnificent Agra Fort/Taj Mahal/ Red Fort in the memory of his wife Mumtaz Mahal.
Ans. Shah Jahan built the magnificent Taj Mahal in the memory of his wife Mumtaz Mahal.

3. Shah Jahan built a new city called Fatehpur Sikri/ Daulatabad/Shahjahanabad.
Ans. Shah Jahan built a new city called Shahjahanabad.

4. Aurangzeb’s reign can be roughly divided into four/ three/two
Ans. Aurangzeb’s reign can be roughly divided into two periods.

5. One of the most serious challenges faced by Aurangzeb came from the Sikhs/Marathas/Rajputs in the Deccan.
Ans. One of the most serious challenges faced by Aurangzeb came from the Marathas in the Deccan.

D. State whether the following are true or false:

  1. Jahangir defeated the Rana of Mewar.
     True.                                                                              ’
  2. Jahangir is said to have installed a chain of justice.
    True.
  3. The Peacock Throne was taken to Persia by Nadir Shah.
    True.
  4. The Jama Masjid is said to be the most perfect of Jahangir’s buildings.
    False. Correct: The Jama Masjid is said to be the most perfect of Shah Jahan’s buildings.

E. Answer the following questions in one or two words/ sentences:

1. Why did Jahangir not face any major problems in maintaining his large empire?
Ans. The foundations laid by Akbar were so strong that Jahangir did not have any major problems maintaining the empire.

2. Name Jahangir’s son who rebelled against him.
Ans. The rebellion of his eldest son, Khusrau.

3.Why is Shah Jahan known as the Engineer King?
Ans.Shah Jahan is known as Engineer King due to his work in the field of architecture. During his time magnificent buildings were constructed which are remembered still now. Some of the finest examples of monuments during his reign are — the magnificent Taj Mahal at Agra, the Moti Masjid at Agra Fort and the dignified Jama Masjid at Delhi.

4. Which fort did Shah Jahan build in the new city of Shahjahanabad?
Ans.Red Fort.

5. Who succeeded Shah Jahan as the Mughal emperor?
Ans.Shah Jahan’s third son, Aurangzeb.

6. State any one major cause of the decline of the Mughal empire.
Ans.He spent too much money on military expeditions and building magnificent monuments which drained the royal treasury.

7. What was the nature of Aurangzeb’s Rajput policy in the early years of his reign?
Ans.During the early years of his reign, Aurangzeb followed Akbar’s policy of friendship with the Rajputs. He granted the Rajput rulers high mansabs and tried to win their support.

8. What were the objectives of Aurangzeb’s Deccan policy?
Ans.Aurangzeb wanted to crush the growing powers of the Maratha’s. As these people were veiy strong and courageous and they also did not accept the overlordship of the ruler. This empire was also very vast and prosperous, so Aurangzeb wanted to have it under his control.

9. Why did the annexation of Bijapur and Golconda prove harmful for the Mughal empire?
Ans.It became too vast and unwieldy and brought the Mughals into direct contact with the Marathas.

F. Answer the following questions briefly:

Question 1.
Jahangir fulfilled Akbar’s unrealized imperial dreams by conquering Mewar. Explain.
Answer:
Jahangir sent an expedition against Rana Amar Singh of Mewar who, like his father, Rana Pratap Singh, had refused to acknowledge the overlordship of the Mughal emperor. The Rana of Mewar was defeated. He pledged his loyalty to Jahangir, who treated him with courtesy. He allowed the Rana to retain his territory and appointed his son, Kama, as a military commander in the imperial army. The submission of Mewar established the paramountcy of Mughal authority in Rajputana and marked the fall of the last bastion of Rajput resistance.

Question 2.
To what extent were Jahangir’s Deccan campaigns successful?
Answer:
Jahangir sent an expedition under Prince Khurram who managed to recapture the fort of Ahmadnagar. Prince Khurram was honoured with the title of Shah Jahan (Lord of the World). The war continued and by the end of Jahangir’s reign, Ahmadnagar reasserted its independence and remained outside Mughal control.

Question 3.
What qualities did Nur Jahan possess to make her worthy of her name?
Answer:
Nur Jahan means-light of the world and according to her name she possessed all the qualities like she was intelligent, beautiful, educated and cultured. She was a good poet and designer too. She designed new varieties of fabrics and jewellery. She was also strong and courageous and helped Jahangir to take decisions in matters related to the government.

Question 4.
Nur Jahan was very ambitious and eventually became the power behind the throne. Explain.|
Answer:
Nur Jahan was ambitious and soon became the power behind the throne. Jahangir consulted her on all matters concerning the affairs of the government. Nur Jahan soon became the virtual ruler of the Mughal empire. Graudally, Jahangir left the administration in her hands and spent his time indulging in his addiction to wine and opium. Coins began to be issued jointly in the name of Jahangir and Nur Jahan. Nur Jahan used her positioin and influence to appoint her father, brother and other relatives to important posts in the administration. Her niece, Mumtaz Mahal, was married to Jahangir’s third son, Khurram (Shah Jahan).

Question 5.
Shah Jahan’s reign was an age of splendour and cultural brilliance. In this context, discuss:
(a) Taj Mahal
(b) Red Fort
Answer:
(a) Taj Mahal: It took more than 20 years to complete the Taj Mahal, at a cost of one crore rupees at that time. It is made of pure white marble and is lavishly decorated with semi-precious stones and lace-like screens. It is an octagonal monument with a splendid dome and four slender minerals, set in a beautiful garden,
(b) Red Fort: This building is made of red sandstone. There are many splendid buildings inside the Red Fort. The Diwan-i-Khas is the most impressive. Its ceiling is made of silver. Its walls are made of marble and decorated with gold and semi-precious stones.

Question 6.
Why did Aurangzeb’s Deccan campaign against the Marathas prove to be a ruinous misadventure? What were the long-term consequences of this campaign?
Answer:
The Deccan campaign proved to be a ruinous misadventure that showed lack of political wisdom.
Suspicious by nature, he did not trust his sons and nobles. His officials were like puppets on strings. Aurangzeb’s supervision of every department often bordered on interference. His policy of discrimination between his subjects on grounds of faith also made him unpopular. He was a man of unshakeable convictions and tried very hard to reach his goals by doing what he thought was right. As he lay on his deathbed, he wrote several letters to his son. In one letter he wrote, ‘I know not who I am or why I came into the world … I have not done well for the country or its people . . . I know what punishment will be in store for me to suffer.’ During the first half of the 19th century ce, the great Mughal empire decayed and disintegrated. The Mughal emperors lost their power and glory and their vast empire finally shrank to a few square miles around Delhi.

Question 7.
Why did Aurangzeb fail as a ruler?
Answer:
Aurangzeb possessed qualities of an ideal man but he was failure as a ruler. Like his father he was not able to follow the policy of religious tolerance and friendship. His list of enemies not only included Rajput’s but also Sikhs and the Marathas. He was also very suspicious by nature, which was not liked by his officials. His policy of discrimination with his subjects also made him an unpopular ruler.

Question 8.
Briefly explain the negative aspects of Shah Jahan’s reign that eventually led to the decline of the Mughal empire.
Answer:
The policy of religious tolerance and friendship with the Rajputs was continued by Shah Jahan.Behind the glamour and the glitter of Shah Jahan’s reign, however, lurked some disturbing shadows.

  1. Shah Jahan’s military expeditions to Central Asia and Kandahar and the extravagant building projects drained the royal treasury.
  2. To improve the country’s financial resources, heavier taxes were imposed on the peasantry.
  3.  According to Bernier, the French traveller, many villages were mined and left desolate. This setback to agriculture became a major cause of the decline of the Mughal empire.
  4.  The failure of military campaigns during this period was an indication of the decline of the military might of the Mughals.
  5. The administrative machinery had grown in size but corruption had crept in.

G Picture study:

This is a picture of a 17th century-CE monument, built in red sandstone by a Mughal emperor.
ICSE Solutions for Class 7 History and Civics - Jahangir, Shah Jahan and Aurangzeb 7

Question 1.
Identify the monument.
Answer:
Red Fort.

Question 2.
Where is it located?
Answer:
Old Delhi.

Question 3.
Who built this monuments?
Answer:
ShahJahan.

Question 4.
Name two important buildings inside this monument.
Answer:
(a) Diwan-i-Khas
(b) Diwan-i-Aam

Question 5.
Mention its important features.
Answer:
Important features are as:
The Diwan-i-Khas is the most impressive. Its ceiling is made of silver and its walls are made of marble decorated with gold and semi-precious stones.
Diwan-i-Aam was Shah Jahan’s Peacock Throne. It had a canopy supported by twelve emerald pillars, each bearing two peacocks studded with gems. This golden throne, which took 7 years to complete, was taken to Persia by Nadir Shah in 1739 ce.

Selina Concise Biology Class 8 ICSE Solutions – Ecosystems

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Selina Concise Biology Class 8 ICSE Solutions – Ecosystems

ICSE SolutionsSelina ICSE SolutionsML Aggarwal Solutions

APlusTopper.com provides step by step solutions for Selina Concise ICSE Solutions for Class 8 Biology Chapter 4 Ecosystems. You can download the Selina Concise Biology ICSE Solutions for Class 8 with Free PDF download option. Selina Publishers Concise Biology for Class 8 ICSE Solutions all questions are solved and explained by expert teachers as per ICSE board guidelines.

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Selina Concise ICSE Solutions for Class 8 Biology Chapter 4 Ecosystems

REVIEW QUESTIONS

Multiple Choice Questions:

1. Put a tick mark (✓) against the correct alternative in the following statements:

a. The term “ecosystem” is derived from the Greek word “Oikos” meaning.

  1. Body weight
  2. Food
  3. House
  4. Size

b. Rat in any food chain would occupy the position of

  1. Tertiary consumer
  2. Secondary consumer
  3. Primary consumer
  4. Producer

c. Evergreen broad-leaved trees are characteristic of

  1. Tropical rain forests
  2. Temperate deciduous forests
  3. Coniferous forests
  4. All of the above types of forests.

Short Answer Type:

1. Mention if the following statements are true (T) or false (F).
(a) Snakes are primary consumers (T/F)
(b) Some humans are strictly primary consumers & some others are of other types of consumers also (T/F)
(c) No ecosystem can survive without light (T/F)
(d) Cattle go to ponds for drinking water, so they are a constituent of pond ecosystem (T/F)

Answer:

(a) Snakes are primary consumers (F)
No the snakes are not primary consumers as snakes eat rats and frogs as these are primary consumers which eat plant products. As snakes eat the primary consumers so the snakes are secondary consumers.

(b) Some humans are strictly primary consumers and some others are of other types of consumers also (T)
It is true that humans are vegetarians and eat plants or plant products. So these humans are vegetariBut there are certain humans which eat the flesh or eggs of other animals. These are carnivores and humans living plants are called Herbivores.

(c) No ecosystem can survive without light (T)
The plants and animals and micro-organisms present at a place and interacting with the atmosphere like sun light, air, water, soil and warmth and dwelling at a place like, pond, desert, forest, rock form the ecosystem as pond ecosystem, desert ecosystem forest ecosystem. So ecosystem cannot survive without the presence of light. As the flora (plants) living in that ecosystem can only make food in the presence of light and the animals (Fauna) living in that ecosystem get the food from the plants of that ecosystem. So flora in that area cannot survive in that area without light and animals living in that area will not get the food and the plants and animals will perish and the ecosystem cannot survive.

(d) Cattle go to ponds for drinking water, so they are a constituent of pond ecosystem (F)
Cattles likes tigers, lions, cows, deers, buffaloes, go to take water from the pond and return to their dwellings as tigers, deers etc. come to the forest so they form a forest ecosystem. But plants like hydrilla, vallineria, lotus etc. and animals like frogs, beetles, fish live in the pond and form the pond ecosystem. But animals like buffalo which come only to take~water cannot form a part of the pond ecosystem.

2. Match the items in Column I with as many items as possible in Column II.
Selina Concise Biology Class 8 ICSE Solutions – Ecosystems 1
Selina Concise Biology Class 8 ICSE Solutions – Ecosystems 2
Answer:

Selina Concise Biology Class 8 ICSE Solutions – Ecosystems 3
3. Rewrite the following in their correct sequence in a food chain:
(a) Snake → Grasshopper → Grass → Frog
(b) Grass → Tiger → Deer
(c) Snake → Peacock → Rat → Wheat

Answer:

(a) Grass → Grasshopper → Frog → Snake
(b) Grass → Deer → Tiger
(c) Wheat → Rat → Snake → Peacock

Long Answer Type:

Question 1.
Differentiate among primary, secondary and tertiary consumers. Give one example of each in a food chain.
Answer:
All plants produce food through photosynthesis and are categorised as self food producers i.e. these are autotrophs. There are plant eating animals called herbivores as Rabbits, deers, pigeons, cows, buffaloes etc. and insects like grasshoppers, bees, butterflies and crickets also eat plants or plant products as fruits, flowers, pollen grains and plant juices. Such animals are called primary consumers.
Animals like tigers, lions, wolves, lizards, frogs eat the primary consumers. Birds vultures, kites, eagles eat the primary consumer, (i.e. These birds are well eat the flesh of many birds like pigeons, sparrows.) These animals or birds are called secondary consumers.
Animals like snakes are eaten by the peacocks, they eat the secondary consumers and are called tertiary consumers.
Owls, eagle are top carnivore. So it is quaternary consumer.

Question 2.
Define the term (a) flora and (b) fauna.
Answer:
Flora: Plants occurring in a particular is called flora of that area i.e. vegetative growth forms flora. Flora deals with plants.
Fauna: The animals occurring in a area form the fauna of that area. Fauna deals with animals.
Flora and fauna of an area is the plants and animals found in that area.

Question 3.
List any three members each of the flora and fauna of tropical rain forests.
Answer:
Tropical rain forest are on western coast of India and in the north, east.
Flora: bamboos, ferns, shrubs (Evergreen trees).
Fauna: leopards, jungle cats, monkeys, snakes, flying squirrels, insects, snails, centipedes, millipedes.

Question 4.
Define the following terms and give two examples in each case.
(a) Symbiosis
(b) Parasitism
(c) Predation
Answer:
(a) Symbiosis: It refers to relationships between organisms of different species that show on intimate association with each other. Symbiotic relationships provide atleast one of the participating species with a nutritional advantage.
Examples of Symbiosis Relationships are of Fungus and photosynthestic alga and Microbes and cattle.

(b) Parasitism: Parasitism is a type of symbiotic relationship between organisms of different species where one organism, the parasite, benefits at the expense of the other, the host. Examples of Parasitism are 4 tapeworms, flukes, the plasmodium species and mosquitoes.

(c) Predation: A predator is any consumer that kills and eats another living organism in order to obtain energy. The organism being eaten is called the prey.
Examples are Lions, Deer, Wolves, Eagles.

Selina Concise Biology Class 6 ICSE Solutions – Digestive System

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Selina Concise Biology Class 6 ICSE Solutions – Digestive System

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APlusTopper.com provides step by step solutions for Selina Concise ICSE Solutions for Class 6 Biology. You can download the Selina Concise Biology ICSE Solutions for Class 6 with Free PDF download option. Selina Publishers Concise Biology for Class 6 ICSE Solutions all questions are solved and explained by expert teachers as per ICSE board guidelines.

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Selina Concise ICSE Solutions for Class 6 Biology Chapter 4 Digestive System

Synopsis:

  • The food we consume fall into seven different catagories.
    1. carbohydrates
    2. fats
    3. proteins
    4. minerals
    5. vitamins
    6. water
    7. roughage
  • The process of nutrition is conducted in five steps
    1. ingestion
    2. digestion
    3. absorption
    4. assimilation
    5. egestion
  • When some part of food is chewed, the tongue makes it a spherical mass called Bolus.
  • Peristalsis is a wave of constriction in the circular muscles in the wall of the gut to push the food further into the food canal.
  • The food canal is also called alimentary canal which starts from the mouth and ends at the anus.
  • The digestive glands include
    1. Salivary glands
    2. Liver
    3. Pancreas
  • The teeth which are similar in size and shape are called homodont teeth.
    They are usually found in fishes, frogs, reptiles etc.
  • The last molar on each side in each j aw is called wisdom tooth which appears at the age of 17-20 years.
  • The human teeth develop in two sets; the first set is called milk teeth or temporary teeth while the second set which replaces the milk teeth are called permament teeth.
  • The milk teeth are twenty in number while the permament are thirty two in number.
  • The part of the teeth which can be seen is called crown while the part which is fixed in the jaw is called root.
  • The tooth is made up of:
    1. enamel
    2. dentin
    3. pulp
  • The hardest substance of the body is called Enamel.
  • The yellow, stick substance found on the teeth due to poor oral hygeine is called plaque. It consists of sugar and bacteria.
  • Mineralised or hard plaque is called tartar.
  • The functions of tongue are:
    1. manipulates food while chewing
    2. helps in tasting the food
    3. mixes food with saliva
    4. cleans the teeth.
    5. helps in speaking.
  • The enzyme contained in saliva is called amylase which digests starch into glucose.
  • The food pipe is the oesophagus. No digestion takes here
    Selina Concise Biology Class 6 ICSE Solutions - Digestive System 1
    Selina Concise Biology Class 6 ICSE Solutions - Digestive System 2
  • The organ which serves for both digestion and absorption of the food is small intestine.
  • The small intestine is 7 metres long while the large intestine is 1.5 metres long.
  • No enzyme is secreted by the large intestine.
  • Glucose, amino acids, vitamins and minerals are transported to the liver.
  • Amino acids are used in the production of proteins for growth and repair of tissues.

Review Questions

Multiple Choice Questions :

1. Put a tick (✓) against the most appropriate alternative in the following statements.

(1) The teeth which help in tearing the food are the:
(a) Incisors
(b) Canines
(c) Premolars
(d) Molars

(ii) Last molar tooth in human beings is called:
(a) Adult tooth
(b) Wisdom tooth
(c) Child tooth
(d) Elders tooth

(iii) The hardest substance in your body?
(a) Dentine
(b) Bone
(c) Cement
(d) Enamel

(iv) Saliva converts starch into:
(a) Glucose
(b) Sucrose
(c) Maltose
(d) Lactose

(v) Proteins of the milk are converted into curd by the enzyme:
(a) Trypsin
(b) Rennin
(c) Pepsin
(d) Steapsin

(vi) Bile juice ¡s produced by :
(a) Stomach
(b) Liver
(e) Pancreas
(d) Gall bladder

1. Write True or False in the following statements.

  1. Molars help in cutting and tearing food.
    False
    Correct — Molars help in finer crushing and grinding.
  2. Carbohydrates are digested into glucose.
    True
  3. Proteins are digested into fatty acids.
    False 
    Correct — Proteins is digested into amino acids.

2. Fill in the blanks.

  1. The teeth called are a total of four in number on the sides of incisors.
  2. The teeth called canines are a total of four in number on the sides of incisors.
  3. Pharynx is a common opening of food pipe and wind pipe.
  4. Molars are meant for crushing the food.
  5. Incisors are used for biting and cutting the food.
  6. The canines are used for tearing the food.
  7.  The premolars and molars are used for crushing and grinding the food.
  8.  In an adult human, there are a total of 32 teeth.
  9. The human teeth appear in two sets, the first set is called primary which consists of only twenty teeth.

3. Name the following :

  1. End product of starch after digestion — glucose.
  2. The organ where protein digestion-begins — stomach.
  3. The organ into which the pancreatic juice and the bile juice are poured — small intestine.
  4. The enzyme which digests fat — lipases.
  5. The simplest form of carbohydrates — glucose. ‘
  6. The part of alimentary canal where water from undigested food is absorbed — large intestine.
  7. The end-product of proteins after digestion — amino acids.

4. Identify and name the four type of teeth shown below and give their functions.
Answer :
Selina Concise Biology Class 6 ICSE Solutions - Digestive System 3
A — incisor
Function -Its major function is biting and cutting of food.
B — canine
Function — Its major function is tearing of the food.
C — pre-molar
Function — Used for crushing and grinding of food.
D — molar
Function — Used for crushing and grinding of food.

5. State whether the following statements are True or False.

(i) Wisdom tooth appears at the age of 5-6 years when the child starts going to school.
(ii) The temporary set of teeth includes incisors, canines and premolars only.
(iii) The ducts from the salivary glands open into the duodenum.
(iv) Saliva changes starch into maltose.
Answer :
(iv) True (V) Saliva changes starch into maltose.

6.Fill in the blanks in the table (1-5) by selecting the suitable names of substances from the list given below:
(steapsin, peptones, fatty acids, proteoses, protein).
Selina Concise Biology Class 6 ICSE Solutions - Digestive System 4
Answer :
Selina Concise Biology Class 6 ICSE Solutions - Digestive System 5

Question 7.
(i) Name the juice secreted by the liver.
Ans. Bile
(ii) Name the organ where this juice is temporarily stored.
Ans. Gallbladder
(iii) What is the main function of this juice ?
Ans. The main function of bile is digestion of fats.

Question 8.
Name the three enzymes found in pancreatic juice.
(i)….. (ii)….. (iii) ……
Answer :
(i) Starch digesting — amylase
(ii) Protein digesting — trypsin
(iii) Fat – digesting — lipases

Question 9.
Name the three regions of the large intestine.
Answer :

  1. Caecum
  2. Colon
  3. Rectum

Question 10.
Given alongside is the diagram of the human alimentary canal.
(i) Name the parts 1-11 indicated by guidelines.
1. … 2. … 3. … 4. … 5. … 6. …
7. … 8. … 9. … 10. … 11 ….
(ii) State the function of the juice secreted by the part 1.
(iii) State the function of the three enzymes found in the juice secreted by part 3.
Selina Concise Biology Class 6 ICSE Solutions - Digestive System 6
Answer :
(i) 1 Stomach
2—Bile duct
3 — Pancreas
4 — Large intestine
5 — Small intestine
6 — Rectum
7—Appendix
8 — Pancreatic duct
9— Gall Bladder
10—Liver
11—Anus
(ii) The gastric juice being acidic kills the germs and activates pepsin.
(iii)

  1. amylase — digests starch
  2. trypsin — digests protein
  3. lipase — digests fat

Long Answer Questions
Question 1.
Define the term nutrition.
Answer :
The process by which living beings receive the food and utilise it to grow and become healthy is called nutrition.
On the basis of nutrition, living beings can be classified into the following types:

  1. Holozoites
  2. Parasites
  3. Saprophytes
  4. Symbionts

Holozoits can be further classified into

  1. herbivores
  2. carnivores
  3. ommivores

Question 2.
What is the role of the liver and the pancreas respectively in the digestion of food ?
Answer :

  1. Liver: It produces a green yellow fluid called the bile which emulsify fats making it easy to be digested. The bile also contains sodium bicarbonate which neutralises the acid of food coming from the stomach and makes it alkaline.
  2. Pancreas: It produces the digestive juice called the pancreatic juice which acts on carbohydrates, proteins and fats and convert them into simpler units called glucose, amino acids and fatty acdis respectively.

Question 3.
Name the digestive juice secreted by the stomach and give its function.
Answer :
The digestive juice secreted by the stomach is the gastric juice.
The gastric juice contains

  1. — water
  2. — hydrochloric acid
  3. — enzyme

Which have the following roles :

  1. Hydrochloric acid serves to kill the germs and activates pepsin.
    Pepsin converts proteins into peptones and proteoses.
  2. Enzyme rennin converts the milk caesin into curd.

Answer the following questions:
Question 4(i).
(i) Name the types of teeth seen in humans.
Answer :
Human teeth are of four kinds:

  1. Incisors are the four front teeth at the middle of each jaw. They are chisel-shaped for biting and cutting.
  2. Canines are one on either side of the incisors in each jaw. They are pointed for tearing the food.
  3. Premolars are two on each side of canines in each jaw. They help in crushing and grinding the food.
  4. Molars are the last three teeth on each side in each jaw. They have broad uneven surface for finer crushing and grinding of ingested food.

Question 4 (ii).
How is the small intestine best suited for the digestion and absorption of food ?
Answer :
The small intestine’s inner lining contain a large number of tiny finger-like projections called villi. The villi greatly increases the inner surface area for the absorption of digested food.

Question 4(iii).
What do you mean by absorption of food ?
Answer :
The absorption of food means to pass the digested food products into the blood system and lymph vessels to be used further by body for various life functions.

Question 5.
Define the following terms
Egestion, digestion, assimilation.
Answer :
Egestion — The process of removal of the undigested food from the body is defined as egestion.
Digestion — The process of breaking the food into smaller and simpler substances so that they can be easily used by the body is called digestion.
Assimilation — The process of using the digested food by the body is called assimilation.

Question 6.
Rewrite the following parts of the human alimentary canal in their correct sequence
Stomach, Oesophagus, Large instestine, Small intestine, Pharynx.
Answer :
Pharynx — Oesophagus → Stomach → Small-
intestine → Large intestine.

Question 7.
What is the fate of excess glucose in our body ?
Answer :
The excess glucose is converted by the liver into insoluble glycogen and stores it, whenever required. Liver can reconvert the glycogen into glucose.

Question 8.
Define the term ‘digestion’.
Answer :
The process of converting the complex food substances into simpler and smaller units so that they can be easily utilised by the body is defined as digestion.
e.g. proteins are converted to amino acids.

Question 9.
State the four ways in which saliva is useful to us.
Answer :
The four ways in which saliva is useful to us are:

  1. Moistens and lubricates the oral cavity and the tongue to make speaking and swallowing easy.
  2. Acts as a solvent, dissolving some part of food to stimulate taste
  3. Cleans the mouth and destroys germs
  4. Initiates digestion by converting starch into simpler form, maltose.

Question 10.
Food are classified into three groups on the basis of the function they perform in our body. Name the three categories, and briefly give their functions. Also give their two sources each.
Answer :
Function

  1. energy giving food
  2. bodybuilding food
  3. regulatory and protective foods

Nutrient

  1. carbohydrates and fats
  2. proteins
  3. vitamins and minerals

Food

  1. cereals, fats, sugar
  2. pulses, milk, meat chicken
  3. fruits and vegetables

Selina Concise Biology Class 7 ICSE Solutions – Photosynthesis and Respiration

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Selina Concise Biology Class 7 ICSE Solutions – Photosynthesis and Respiration

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APlusTopper.com provides step by step solutions for Selina Concise ICSE Solutions for Class 7 Biology. You can download the Selina Concise Biology ICSE Solutions for Class 7 with Free PDF download option. Selina Publishers Concise Biology for Class 7 ICSE Solutions all questions are solved and explained by expert teachers as per ICSE board guidelines.

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Selina Concise ICSE Solutions for Class 7 Biology Chapter 4 Photosynthesis and Respiration

Synopsis —

  • The process of preparing or synthesising food using water from the soil and carbon dioxide from the air, together chlorophyll and sunlight is called photosynthesis.
  • Photosynthesis occurs in the mesophyll cells of the leaf. These cells contain numerous plastids called chloroplasts.
  • With in the plastids is present the green pigment called chlorophyll.
  • On the lower surface of the leaf are numerous pores called stomata, which open into small air cavities inside the leaf.
  • Stomata are tiny openings found mainly on the lower surface of leaves. These openings are surrounded by a pair of bean¬shaped cells called guard cells.
  • All plants have a transport system called vascular system. It is composed of two types of tissues called xylem and phloem.
  • There are two end-products of photosynthesis :
    • Glucose (C6H12O6)
    • Oxygen
  • The energy released during respiration is stored as chemical energy in the form of ATP — adenosine tri-phosphate.
  • Aerobic respiration —
    C6 H12O6+6O2  →  6CO2+6H2O+38ATP
    Anaerobic respiration —
    C6H12O6 →  2C2H5OH+2CO2+2ATP
  • During vigorous exercise, the cells respire anaerobically and form lactic acid which accumulate in the muscle cells causing fatigue and pain.
  • Cellular respiration is called internal respiration which takes place in the cells of living organisms.
    Selina Concise Biology Class 7 ICSE Solutions - Photosynthesis and Respiration 1
  • The frog respires through
    1. skinmouth
    2. lining
    3. lungs.
  • The respiratory organs of the fish are gills.
  • Transpiration is the loss of water in the form of water vapour from the aerial parts of the plant.
  • Transpiration occurs through stomata.
  • The factors which affect the rate of transpiration are 
    1. Sunlight
    2. Temperature
    3. Wind
    4. Humidity
  • The significance of transpiration
    •  Maintain the concentration of the sap inside the plant body.
    • Causes cooling effect

Review Questions

Multiple Choice Questions
1. Put a tick (✓ ) against the most appropriate alternative in the following statements.
(i) Carbohydrates are stored by plants in the form of:
(a) Vitamins
(b) Proteins
(c) Fats
(d) Glucose 

(ii) Stomata are present on the surface of:
(a) Leaves
(b) Roots
(c) Stem
(d) Flower petals

(iii) Which one of the following is an end-product of photosynthesis ?
(a) Fructose
(b) Glucose
(c) Cellulose
(d) Lactose

Short Answer Questions

1. Why do leaves generally look green ?
Answer:
The green colour of a leaf is due to the presence of chlorophyll.

2. Which four of the following are needed for photosyn-thesis in a leaf:
(i) Carbon dioxide:
(ii) Oxygen:
(iii) Nitrates :
(iv) Water:
(v) Chlorophyll:
(vi) Soil:
(vii) Light:
Answer:
(i) Carbon dioxide: from air
(iv) Water: from soil
(v) Chlorophyll: contained in leaf
(vii) Light: from sunlight

3. What is the source of energy for photosynthesis ?
Answer:
Light is the ultimate source of energy in photosynthesis because plants take in the sunlight CO2 and H2O and converts it into glucose.

4. Which gas is taken in and which one is given out by the leaf in bright sunlight ?
(i) Taken in :
(ii) Given out:
Answer:
(i) Carbon dioxide
(ii) Oxygen

5. Suppose we compare the leaf with a factory, match the items in Column A with those in Column B.
ColumnA Column B
Selina Concise Biology Class 7 ICSE Solutions - Photosynthesis and Respiration 2

Answer:
Selina Concise Biology Class 7 ICSE Solutions - Photosynthesis and Respiration 3

6. State whether the following statements are True or False:

(i) Green plants prepare their food by using two raw materials, oxygen and water.
False. Green plants prepare their food by using raw materials, CO, chlorophyll and water.
(ii) The chlorophyll enables the plants to use light energy.
 True
(iii) The free oxygen in the atmospheric air is the result of photosynthesis.
 True
(iv) Photosynthesis occurs only in chlorophyll-containing parts of the plant.
True

7. Differentiate between aerobic and anaerobic respiration. Write the overall chemical equations of the two kinds of respiration in plants.
(i) Aerobic:
(ii) Anaerobic:
Answer:
Aerobic respiration

  1. It occurs in the presence of oxygen.
  2. Here there is complete breakdown of glucose releasing carbon-di-oxide, energy. water and energy.
  3. More energy is released (38 ATP).

Anaerobic respiration

  1. It occurs in the absence of oxygen.
  2. There is partial breakdown of glucose into ethyl alohol, carbon-di-oxide and
  3. Lesser energy is released (2 ATP).

(i) Aerobic respiration:
Selina Concise Biology Class 7 ICSE Solutions - Photosynthesis and Respiration 4
(ii) Anaerobic respiration:
Selina Concise Biology Class 7 ICSE Solutions - Photosynthesis and Respiration 5
Question 8.
 Explain how photosynthesis is different from respiration.
Answer:
Photosynthesis

  1. Anabolic process
  2. Food is produced here.
  3. Oxygen is by-product.
  4. Chlorophyll and sunlight are required.
  5. Occur only during daytime.
  6. Occurs in green plants only.

Respiration

  1. Catabolic process
  2. Food is broken down form here to release energy
  3. Carbon-di-oxide is the by-product.
  4. Chlorophyll and sunlight are notrequired.
  5. Occurs all the time
  6. Occurs in all living beings including plants.

Photosynthesis :
Selina Concise Biology Class 7 ICSE Solutions - Photosynthesis and Respiration 6

Respiration:

C6H12O6+6O→6CO2+6H20+energy

Question 9.
 Do the plants respire all day and night or only during the night ?
Answer:
The plants respire only during the night. Plants take in oxygen and give out carbon dioxide. Hence, there is some truth in the belief that one should not sleep under the trees at night.

Question 10.
 What happens to the energy liberated during respiration?
Answer:
The energy liberated during respiration is utilised for carrying out various life processes.
Some of the energy liberated during the breakdown of 03 the glucose molecule, is in the form of heat, but a large part of it is converted into chemical energy called Adenosine Triphosphate (ATP). Any activity inside the cell is carried out by the energy released by these ATP molecules.

Long Answer Questions

Question 1.
In order to carry out photosynthesis, what are the substances that a plant must take in ? Also mention their sources.
Answer:
For preparing food, the plants require the following :

  1. Water (from soil)
  2. Carbon dioxide (from air)
  3. Chlorophyll (contained in the leaf)
  4. Energy (from sunlight)

The process of preparing or synthesising food using water from the soil and carbon dioxide from the air, together chlorophyll and sunlight is called photosynthesis. This entire process is a series of complex chemical reactions Photosynthesis is represented as follows:
Selina Concise Biology Class 7 ICSE Solutions - Photosynthesis and Respiration 7

Question 2. 
What is the role of chlorophyll in photosynthesis ?
Answer:
This pigment is of utmost importance as it absorbs the sunlight which provides energy for the process of photosynthesis occurs inside the chloroplast of the leaf.

Question 3.
Do plants need oxygen ? If so, what is its source ?
Answer:
Yes plants need oxygen, all the free oxygen in the atmospheric air is the result of photosynthesis. No animal can survive without oxygen as it is needed for respiration. Even the plants use the same oxygen in dark for their own respiration.

ICSE Solutions for Class 7 Geography Voyage – Greenhouse Effect and Global Warming

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ICSE Solutions for Class 7 Geography Voyage – Greenhouse Effect and Global Warming

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APlusTopper.com provides step by step solutions for ICSE Solutions for Class 7 Geography Voyage. You can download the Voyage Geography ICSE Solutions for Class 7 with Free PDF download option. Geography Voyage for Class 7 ICSE Solutions all questions are solved and explained by expert teachers as per ICSE board guidelines.

ICSE Solutions Class 7 Geography History & CivicsMathsPhysicsChemistryBiology

DISCUSS

Collect rainfall data from the website of Indian Meteorological Department (IMD) for Mumbai, Chennai, Delhi and Kolkata and discuss how rainfall patterns have changed in the last 5 years.
Answer:
ICSE Solutions for Class 7 Geography Voyage Chapter 4 Greenhouse Effect and Global Warming 1
Mumbai receives maximum rainfall in 2016 and minimum rainfall in 2012.
Chennai receives maximum rainfall in 2013 and minimum rainfall in 2012.
Delhi receives maximum rainfall in 2013 and minimum rainfall in 2014.
Kolkata receives maximum rainfall in 2013 and minimum rainfall in 2014.

VALUES AND LIFE SKILLS :

We need to understand that global warming, climate change, acid rain and ozone depletion are all happening because of our dependence on fossil fuels and CFC-based technologies. Therefore, the need of the hour is to reduce
our dependence on them.
What can you do in this regard ?
Answer:
The ways to reduce our dependency on them are :

  1. By using materials such as bamboo, recycled metal and organic paints in construction of buildings.
  2. By using solar energy to heat and light homes and offices.
  3. By using clean fuel like CNG and unleaded petrol to run vehicles.
  4. By making changes in everyday practices such as
    (a) choosing to travel in public vehicles, biking, walking or using a car pool.
    (b) buying energy efficient household appliances.
    (c) replacing light bulbs with CFL bulbs.

EXERCISES

A. Fill in the blanks.

1. Carbon dioxide and methane, nitrous oxide, water vapour and CFCs are examples of greenhouse gases.
2. Global Warming is a major cause of climate change.
3. The increase in earth’s temperature is called global warming.
4. The layer of atmosphere where ozone is found is called stratosphere.
5. The ozone layer protects us from the ultraviolet rays of the sun.

B. Write True or False.

1. Aeroplanes flying in the sky cause global warming.
Answer. True.

2. Forest fires do not cause global warming.
Answer. False.
Correct : Forest fires do cause global warming.

3. Ozone is found in the troposphere.
Answer. False.
Correct : Ozone is found in the stratosphere.

4. The ozone layer is harmful for humans and animals.
Answer. False.
Correct : The ozone layer is not harmful for humans and animals.

5. CFCs and BFCs protect the ozone layer.
Answer. False.
Correct : CFCs and BFCs deplete the ozone layer.

C. Choose the correct option.

Question 1.
Oxygen/Carbon dioxide is a greenhouse gas.
Answer:
Carbon dioxide is a greenhouse gas.

Question 2.
Use of fossil fuels/hydroelectricity causes global warming.
Answer:
Use of fossil fuels causes global warming.

Question 3.
Cattle release methane / CFCs.
Answer:
Cattle release methane.

Question 4.
Global warming will reduce/increase climate change.
Answer:
Global warming will increase climate change.

Question 5.
The ozone layer is found between 20 and 40/40 and 60 km above the earth’s surface.
Answer:
The ozone layer is found between 20 and 40 and above the earth’s surface.

D. Match the following

ICSE Solutions for Class 7 Geography Voyage Chapter 4 Greenhouse Effect and Global Warming 2
Answer:
ICSE Solutions for Class 7 Geography Voyage Chapter 4 Greenhouse Effect and Global Warming 3

E. Answer the following questions in brief 

Question 1.
Why do we call carbon dioxide a greenhouse gas?
Answer:
Carbon dioxide is called greenhouse gas because it absorbs
Infrared radiations. A greenhouse gas is a gas in an atmosphere that absorbs and emits radiation within the thermal infrared range.

Question 2.
Name two more greenhouse gases.
Answer:
Methane and water vapour are other greenhouse gases.

Question 3.
How will countries like Bangladesh and Thailand be affected by global warming?
Answer:
Climate change will cause melting of polar ice caps with huge chunks of icebergs several kilometres across breaking off from the mainland. This is already taking place around the Arctic and in Antarctica. The result will be an increase in the volume of ocean waters. Countries like Bangladesh, Thailand and Malaysia and the Southeastern parts of USA like the States of Florida and Louisiana would be swamped by flood water along its shores.

Question 4.
What is responsible for causing a hole in the ozone layer?
Answer:
The release of large amount of CFCs or chlorofluorocarbons and BFCs or bromofluorocarbons by industries are responsible for the formation of holes in the ozone layer.

Question 5.
Name some diseases that are caused due to exposure to ultraviolet rays of the sun.
Answer:
Exposure to UV rays can cause sunburn, cataract, hair loss, skin cancer and birth deformities.

F. Answer the following questions in one or two paragraphs 

Question 1.
How is the greenhouse effect created?
Answer:
The ‘greenhouse effect’ takes place when the ‘sun’s rays heat the earth. This heat is absorbed by the surface of the earth and some of it is radiated back into the atmosphere. However, a part of this heat is trapped in the atmosphere by gases such as water vapour, carbon dioxide and methane while the rest escapes into space. These gases let in light from the sun but prevent the heat from escaping like the glass walls of a greenhouse. They also act like a mirror and reflect back to the earth some of the trapped heat energy. The more greenhouse gases (GHGs) are present in the atmosphere, the more heat is trapped, subsequently making the earth warmer.

Question 2.
State three causes that have led to an increase in greenhouse gases in the atmosphere.
Answer:
The causes that have led to the increase in greenhouse gases (GHGs) are:

  1. Increase in industries
  2. Increase in deforestation
  3. Increase in atmospheric pollution due to emissions from chimneys of factories
  4. Increase in natural disasters like floods, volcanic eruptions and earthquakes that release large amounts of smoke, dust and gases into the atmosphere
  5. Increase in the methane content of the atmosphere because of large-scale cattle rearing, since cattle release methane
  6. Expansion of cies and towns

Question 3.
What do you understand by the term ‘global warming’?
Answer:
The greenhouse gases in the atmosphere trap a part of the heat radiated back by the earth, increasing its temperature. The increase in the earth’s temperature is called global warming.

Question 4.
State some anthropogenic (man-made) causes of global warming.
Answer:
Man-made causes of global warming ‘include burning of fossil fuels, cutting of forests, using refrigerators, air conditioners, aerosols, factories belching smoke, increase in methane content of the atmosphere because of large-scale cattle rearing, expansion of cities and towns.

Question 5.
Global warming does not augur well for our planet earth. State at least three reasons to support this statement.
Answer:
Global warming is not good for our planet as

(a) It will worsen climate changes leading to food shortages.
(b) Many forms of wildlife are now’ at risk and since climate change and deforestation are causing disappearance of their habitat.
(c) Climate change will cause melting of polar caps resulting in the increase in the volume of ocean waters.

G. Picture study.
ICSE Solutions for Class 7 Geography Voyage Chapter 4 Greenhouse Effect and Global Warming 4

Question 1.
Which region of the world is seen in the picture?
Answer:
Antarctica and Arctic Poles.

Question 2.
How is it going to be affected by global warming?
Answer:
Global warming causes melting of polar ice-caps with huge chunks of icebergs several kilometres across breaking off from the mainland resulting in increase in volume of ocean waters. The increase in the volume of ocean waters will result in rising of sea levels. Countries like Bangladesh, Thailand and Malaysia and the Southeastern parts of USA like the States of Florida and Louisiana would be swamped by flood water along their shores.

LETS DO SOMETHING

Question 1.
Imagine that you are an active member of the Greenpeace. Write a two-page appeal addressed to the Prime Minister of India stating why you think that increasing number of vehicles on roads will be disastrous to the nation in the long run.
Answer:
August 25, 2017,
Mr. Narendra Modi,
Prime Minister of India
Dear Prime Minister Modi,

It is with great optimism and hope that we are following news about the meeting you will have with U.S. President Trump, at this critical time in our planet’s future. 2017 is the year for making decisive commitments towards tackling climate change together. As the elected leader of the world’s largest democracy, and a country with much to lose from run away climate change, the hopes of 1.3 billion Indian citizens rest on you. Along with them, and the millions of people worldwide who will inevitably be affected by decisions made this year, we hope you will successfully push the United States, and the developed world, towards an ambitious and equitable global agreement to rein in climate change.

We congratulate you on setting new and ambitious renewable energy targets, and urge a focus on decentralized renewable energy as the fastest, most cost-effective way to tackle India’s energy poverty challenge. At the same time, we believe that continued growth in coal power is not in the interests of common Indians as it imposes a significantly higher cost on people’s health, livelihood of communities and the environment, and will prove far more expensive than renewable energy. We hope you will secure much-needed support from global partners, civil society and investors – including the United States administration – to realize these renewable energy goals.

Being the member of the Greenpeace, I would like to bring in your kind notice that I found that the number of vehicles has increased considerably in India in the past five years, which is one of the sources of pollution. In the recently released World Health Organization (WHO) report on pollution, the situation of the city is not so encouraging in terms of pollution in the air.
Due to increase in number of vehicles over the years, the city roads witness frequent traffic congestions, but above all, the vehicles emitting pollutants are affecting environment badly. The recently-released WHO report shows that India has 2.5 microns of diameter (PM2.5) concentration of 68 micrograms particulate matter per meter cube. However, the WHO guideline values for particulate matter is 10 microgram per meter cube for PM2.5.

“The air pollution consists of many pollutants, among other particulate matter. These particles are able to penetrate deeply into the respiratory tract and therefore constitute a risk for health by increasing mortality from respiratory infections and diseases, lung cancer, and selected cardiovascular diseases,” says the WHO report.

New patients with respiratory problems are constantly being reported in hospitals. Recently, the many big cities are witnessing a flow of traffic on city roads consisting high end cars too. Moreover, as far as public transport is concerned, the government-owned low floor buses could be seen plying on the road emitting black smoke causing problems for pedestrians, bikers and other roadside vendors. Mr. Avinash Chowdhry senior member of Greenpeace took out a rally of school children at Statue

Circle (Mumbai) on the eve of World Environment Day said, “Men’s health is determined by his environment. He is greatest enemy of his own health. Environmental pollution is one of the reasons of cardiovascular diseases, hypertension and diabetes.”
Collaboration between the government and civil society is essential to secure a bright future for India and the planet. Greenpeace looks forward to working with the Indian government on our common objective of ensuring clean, affordable renewable energy for all.

Sincerely,
VeenuGopal,
Interim Executive Director, Greenpeace

Question 2.
Make a collage using pictures or a chart to show the various causes and consequences of global warming.
Answer:
You can take idea from the picture given below and can make a collage of your own.
ICSE Solutions for Class 7 Geography Voyage Chapter 4 Greenhouse Effect and Global Warming 5

Selina Concise Physics Class 6 ICSE Solutions – Simple Machines

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Selina Concise Physics Class 6 ICSE Solutions – Simple Machines

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APlusTopper.com provides step by step solutions for Selina Concise ICSE Solutions for Class 6 Physics. You can download the Selina Concise Physics ICSE Solutions for Class 6 with Free PDF download option. Selina Publishers Concise Physics for Class 6 ICSE Solutions all questions are solved and explained by expert teachers as per ICSE board guidelines.

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Selina Concise ICSE Solutions for Class 6 Physics Chapter 4 Simple Machines

  • Synposis
  • Work is said to be done when a force applied on a body moves it. If the body does not move on applying a force on it, no work is done by the force.
  • The capacity of doing work is called energy.
  • A machine is a device which helps us to do work more easily.
  • A machine enables us to apply a less effort for a load greater than the effort or to apply the effort at convenient point and in a desired direction.
  • Some machines are simple and some are complex.
  • The mechanical advantage of a machine is the ratio of the load to the effort, i.e., Mechanical advantage = Load / Effort
  • Smaller the effort required for a certain load, greater is the mechanical advantage of the machine.
  • The efficiency of a machine is the ratio of the useful work done on the load by the machine to the work put into the machine by the effort, i.e.
    Efficiency = Work output / Work input
  • The efficiency of an ideal machine is 1 (or 100 per cent).
  • The efficiency of an actual machine is less than 1 because some part of the work put into the machine is lost in overcoming the friction between the moving parts of the machine.
  • A lever is a simple machine which we most commonly use in our daily life. It is a rod which can turn about a fixed point called the fulcrum.
  • The mechanical advantage of a lever is equal to the ratio of the effort arm to the load arm, i.e. Mechanical advantage of a lever = Effort arm / Load arm
    The levers are of three kinds :
    Class I levers which have fulcrum in between the load and the effort.
    Class II levers which have load in between fulcrum and the effort.
    Class III levers which have effort in between the fulcrum and the load.
  • The mechanical advantage of class I lever can be 1, more than 1 or less than 1.
  • The mechanical advantage of class II levers is always more than 1.
  • The mechanical advantage of class III levers is always less than 1.
  • A pulley is a simple machine which is used for raising a load up by applying the effort downwards.
  • The mechanical advantage of an ideal pulley is 1. In an actual pulley, due to friction, the mechanical advantage is less than 1 (i.e., the effort is more than the load).
  • The pulley allow us to apply the effort downwards which is a convenient direction.
  • The wheel and axle is a simple machine having a wheel and an axle. The linear motion of axle is obtained by rotating the wheel so as to reduce friction. Example: Steering wheel, screw drivers, water tap etc.
  • An inclined plane is a simple machine which is used to move a load up with a less effort. It is a sloping (or slanting) surface.
  • Less the slope of the inclined plane, less is the effort needed to push a load up.
  • The mechanical advantage of an inclined plane is greater than 1 (i. e. a less effort is required to push a heavy load up an inclined plane).
  • A wedge is a sharp edge formed by joining the two inclined planes together. Example: nail, knife, axe, plough etc.
  • A screw is a modified form of an inclined plane.
  • A screwjack is a simple machine having a combination of a screw and a lever. It is used to lift the heavy vehicles such as cars, trucks, buses etc.
  • Machines are used for our convenience. Therefore, we should take proper care of a machine by painting the machine parts to avoid rusting, lubricating its parts to reduce friction etc. This increases the life span of the machine.

Test yourself

A. Objective Questions

1. State whether the following statements are True or False.

(a) A boy does work while pushing a wall.
Answer. False

(b) A machine performs work by itself.
Answer. False

(c) In an ideal machine, work done on load is equal to the work done by effort.
Answer. True

(d) All levers are force multipliers.
Answer. False

(e) A pulley changes the direction of force.
Answer. True

(f) An inclined plane always has the mechanical advantage more than 1.
Answer. True

2. Fill in the blanks

(a) The useful work done by an actual machine is always less than the work done on the machine.
(b) In class II levers, the load is in between fulcrum and effort.
(c) The mechanical advantage of class III lever is always less than 1.
(d) A pulley is used to change the direction of effort.
(e) Mechanical advantage of an inclined plane is always greater than 1.

3. Match the following

Selina Concise Physics Class 6 ICSE Solutions Chapter 4 Simple Machines 1

Answer.

Selina Concise Physics Class 6 ICSE Solutions Chapter 4 Simple Machines 2
Selina Concise Physics Class 6 ICSE Solutions Chapter 4 Simple Machines 3

4. Select the correct alternatives

(a) For an ideal machine, the efficiency is

  1. greater than unity
  2. less than unity
  3. equal to unity
  4. depends on the value of load

(b) Mechanical advantage of a machine is defined as:

  1. Load X Effort
  2. Load / Effort
  3. Load + Effort
  4. Effort / Load

(c) The mechanical advantage of a lever is equal to:

  1. Load arm / Effort arm
  2. Effort arm / Load arm
  3. Load arm + Effort arm
  4. Load arn — Effort arm

(d) A pulley is used because it

  1. has the mechanical advantage greater than one
  2. has 100% efficiency
  3. helps to apply the force in a convenient direction
  4. requires more effort to raise a less load.

(e) Wheel is used with axle because

  1. sliding friction is less than the rolling friction
  2. rolling friction is less than the sliding friction
  3. they work as the inclined plane
  4. They help us to change the direction of force.

B. Short/Long Answer Questions

Question 1.
When is work said to be done by a force ?
Answer:
Work is said to be done when a force moves an obj ect through a distance in its own direction.

Question 2.
What is energy ?
Answer:
Energy: The ability or capacity to do work is called energy.

Question 3.
What do you understand by a machine ?
Answer:
Machine: A machine is a device that allows us to do work with less effort. Machines make our work easier to do. Machines have made our li ves comfortable and faster.

Question 4.
What is the principle on which a machine works ?
Answer:
Principle of a Machine: The work output of a machine is equal to the work input.

Question 5.
State two functions of a machine.
Answer:
Various functions that a machine can perform are:

  1. Changing the direction of applied force — Example: When a flag is hoisted with the help of a pulley.
  2. Changing the magnitude of applied force — Example: Bottle opener multiplies the applied force and much less effort is required to open the cap.
  3. Applying force at a convenient point — Example: In a pair of scissors, the input force is applied at the handle of the scissors which cuts the paper at the other end of the blade.
  4. Changing the speed of an object — Example: While riding a bicycle, force is applied on pedals which multiplies the speed.

Question 6.
Name six simple machines. Give an example of each machine.
Answer:
The Simple Machines and there examples are as follows:

  1. The lever: Examples are a crow bar, claw hammer, a pair of pilers etc.
  2. The Inclined plane: Examples are ramp, staircase, hilly roads etc.
  3. The wedge: Examples are knife, axe, plough, nail etc.
  4. Screw: Examples are A screw.
  5. The wheel and axle: Examples are steering wheel of a car, bicycle pedal etc.
  6. The pulley: Examples are a pulley used in raising a load.

Question 7.
Define the term ‘work input’ and ‘work output’ in relation to a machine.
Answer:
Work input is work done on a machine equal to the effort force times the distance through which the force is applied.
Work output is work that is done by a machine equals resistance force times the distance through which the force applied.
For an ideal machine, the work output is equal to the work input i. e. the efficiency.

Question 8.
Explain the term mechanical advantage of a machine.
Answer:
The mechanical advantage of a machine is the ratio of the load to the effort. In other words
Selina Concise Physics Class 6 ICSE Solutions Chapter 4 Simple Machines 4

Question 9.
Define the term efficiency of a machine.
Answer:
The ratio of the work done by the machine to the work done on the machine is called efficiency of a machine
Selina Concise Physics Class 6 ICSE Solutions Chapter 4 Simple Machines 5
(Work done by a machine is called the output energy and the work done on a machine is called the input energy.)

Question 10.
What is an ideal machine ?
Answer:
A machine is which no part of the work done on the machine is wasted, is called an ideal or perfect machine. Thus, for an ideal machine, the work output is equal to the work input, i.e., the efficiency of an ideal machine is 1 (or 100 per cent).

Question 11.
Can a machine have an efficiency of 100% ? Give a reason to support your answer.
Answer:
Efficiency of a machine is always less than 100% as output energy is always less than the input energy, because some energy is lost to overcome friction.

Question 12.
A machine is 75% efficient’. What do you understand by this statement ?
Answer:
If a machine is 75% efficient, it means that 75% of the work input to the machine is obtained as the useful work output. The remaining 25% of the work input has been lost in overcoming the friction.

Question 13.
What is a lever ?
Answer:
Lever: A lever is a simple rigid bar which is free to move around a point called fulcrum.

Question 14.
Describe three orders of levers giving an example of each. Draw neat diagrams showing the positions of fulcrum, load and effort in each kind of lever.
Answer:
The levers are of three kinds :
Class I levers which have fulcrum in between the load and the effort.
Selina Concise Physics Class 6 ICSE Solutions Chapter 4 Simple Machines 6
Class II levers which have load in between the fulcrum and the effort.
Selina Concise Physics Class 6 ICSE Solutions Chapter 4 Simple Machines 7
Class III levers which has effort in between the fulcrum and the Load
Selina Concise Physics Class 6 ICSE Solutions Chapter 4 Simple Machines 8

Question 15.
What do you mean by the mechanical advantage of a lever ?
Answer:
The mechanical advantage of a lever is equal to the ratio of the effort arm to the load arm. This is also called the principle of a lever.

Question 16.
Which class of lever has the mechanical advantage always more than 1 ? Give an example.
Answer:
The mechanical advantage of class II levers is always more- than 1.
Example – Nut cracker, wheel barrow, bottle opener etc.

Question 17.
Which class of lever has the mechanical advantage always less than 1 ? Give an example.
Answer:
The mechanical advantage of class III levers is always less than 1.
Example: a pair of tongs, sugar tongs, knife, forceps etc.

Question 18.
Give one example of class I lever in each case where the mechanical advantage is

  1. more than 1
  2. equal to 1
  3. less than 1.

Answer:

  1. more than 1: Load arm of pliers
  2. equal to 1: See – saw
  3. less than 1: The load arm of a pair of scissors.

Question 19.
Name the class to which the following levers belong:
Selina Concise Physics Class 6 ICSE Solutions Chapter 4 Simple Machines 9
Answer:
(a) A pair of scissors — Class I lever
(b) a lemon squeezer — Class II lever
(c) a nut cracker — Class II lever
(d) a pair of sugar tongs — Class III lever
(e) a beam balance — Class I lever
(f) an oar rowing a boat — Class I lever
(g) a wheel barrow — Class II lever
(h) a see saw — Class I lever
(i) a pair of pilers — Class I lever
(j) a crow bar — Class I lever

Question 20.
The diagram given below shows the three kinds of levers. Name the class of each lever and give one example of each class.
Selina Concise Physics Class 6 ICSE Solutions Chapter 4 Simple Machines 10
Answer:
Selina Concise Physics Class 6 ICSE Solutions Chapter 4 Simple Machines 11
Examples : The examples of class I levers are : a see saw, a pair of scissors, a pair of pilers, crow bar, common balance, spoon opening the lid of a tin can, handle of a hand pump.
Selina Concise Physics Class 6 ICSE Solutions Chapter 4 Simple Machines 12
Examples : The examples of lever of class II are : nut cracker, wheel barrow, paper cutter, mango, lemon squeezer, bottle opener.
Selina Concise Physics Class 6 ICSE Solutions Chapter 4 Simple Machines 13
Examples: The examples of levers of class III are : a pair of tongs, sugar tongs, knife, forceps,-forearm of a person holding a load, spade for lifting soil or coal.

Question 21.
Draw diagrams to illustrate the positions of fulcrum, load and effort, in each of the following:
(a) a see saw
(b) a beam balance
(c) a nut cracker
(d) a pair of forceps
Answer:
Selina Concise Physics Class 6 ICSE Solutions Chapter 4 Simple Machines 14

Selina Concise Physics Class 6 ICSE Solutions Chapter 4 Simple Machines 15

Selina Concise Physics Class 6 ICSE Solutions Chapter 4 Simple Machines 16

Selina Concise Physics Class 6 ICSE Solutions Chapter 4 Simple Machines 17

Question 22.
How can you increase the mechanical advantage of a lever ?
Answer:
The mechanical advantage of a lever can be increased by increasing the effort arm or reducing the load arm.

Question 23.
How does the friction at the fulcrum affect the mechanical advantage of the lever ?
Answer:
Friction at the fulcrum reduces the mechanical advantage.

Question 24.
State three differences between the three classes of levers.
Answer:
Selina Concise Physics Class 6 ICSE Solutions Chapter 4 Simple Machines 18

Question 25.
What is a pulley ?
Answer:
Pulley: It is a flat circular disc with a groove in its edge and a rope passing through the groove. It is capable of rotating around a fixed point passing through its central axis called axle.

Question 26.
What is the mechanical advantage of an ideal pulley ?
Answer:
In an ideal pulley, the effort applied is equal to the load to be lifted.
i.e. Effort = Load
Mechanical advantage = Load / Effort = 1

Question 27.
The mechanical advantage of an actual pulley is less than 1. Give a reason. What is the justification for using the pulley then ?
Answer:
In an actual pulley due to friction, the mechanical advantage is less than 1 (i.e. the effort is more than the load).
The reason for using the pulley when its mechanical advantage is equal to 1 or less than 1 is that the pulley allows us to apply the effort downwards i.e. in a convenient direction. To raise a load directly upwards is difficult. But with the help of a pulley, the effort can be applied in the downward direction to move the load upwards. One can hang on it to make use of his own weight also in order to apply the effort.

Question 28.
Draw a neat labelled diagram showing a pulley being used to lift a load. How are load and effort related in an ideal situation?
Answer:
To raise a load, the load is attached to one end of the string and the effort is applied at the other end by pulling it is downward direction . as shown in fig.
Selina Concise Physics Class 6 ICSE Solutions Chapter 4 Simple Machines 19

Question 29.
What is an inclined plane? What is its use ? Give two examples where ¡t is used.
Answer:
An inclined plane is a rigid sloping surface over which heavy loads can be raised or lowered to a certain height or depth.
The mechanical advantage of an inclined plane is the ratio of the length of the plank to the vertical height of the load raised. Its value is greater than one. Therefore, an inclined plane acts as a force multiplier. Thus, it can be used to lift heavy loads.
Example : If a heavy box needs to be loaded on a lorry, it is far easier to push it over an inclined plane than to lift it up. Steeper the inclined plane, greater will be the effort required to push up the load.
Sloping ramps, flyovers, roads on hills and staircases are all examples of inclined planes.

Question 30.
What is a screw ? Give two examples.
Answer:
A screw is a simple machine which appears like an inclined plane wound around a rod with a pointed tip.
Examples : ajar lid, a drill.

Question 31.
What is wheel and axle ? Give two examples.
Answer:
The wheel and axle is a simple machine having a wheel and an axle. The linear motion of axle is obtained by rotating the wheel so as to reduce friction. Example: Steering wheel, screw drivers, water tap etc.

Question 32.
How does a wheel help in moving the axle ?
Answer:
Wheel-and-axle arrangement consists of two cylinders of different diameters joined together such that if one is made to rotate, the other also rotates. The axle is a cylindrical rod fixed to the centre of a circular disc-like object called the wheel.
Selina Concise Physics Class 6 ICSE Solutions Chapter 4 Simple Machines 20
This machine acts as a speed multiplier device.
In riding a bicycle, when we apply force on the wheel (by pedal), the fixed axle rotates with it easily. This force that turns the axle produces a much larger movement of the wheel.

Question 33.
What is a wedge ? Give two examples.
Answer:
A wedge is a double inclined plane such that the two sloping surfaces taper to form either a sharp edge or a pointed edge. Examples : A knife, an axe, a chisel.
In some special cases, the number of inclined planes used can be more than two as well. In such cases, the sloping surfaces generally taper to form either a very sharp or a pointed edge to split or pierce materials. Pins, nails and needles are examples of pointed wedges. The front end of a boat is shaped like a wedge so that it can easily cut across the flowing water.
The wedge works on a principle of an inclined plane.

Question 34.
Name the machine to which the following belong :

  1. Beam balance
  2. Lemon crusher
  3. Sugar tongs
  4. Ramp
  5. Door knob
  6. Needle

Answer:

  1. Beam balance — A lever (lever of class I)
  2. Lemon crusher — A lever (lever of class II)
  3. Sugar tongs — A lever (lever of class III)
  4. Ramp — An inclined plane
  5. Door knob — Wheel and axle
  6. Needle — Wedge

Question 35.
What care would you take to increase the life span of a machine which you use ?
Answer:
Taking care of machines: Some of the ways in which machines should be cared for are given below :

  1. Machines should be kept in a clean environment, which is free from dust and moisture.
  2. When not in use, machines should be kept covered to prevent collection of dust on them.
  3. Machines made of iron should be protected from rust by coating them with paint.
  4. The moving parts of a machine should be regularly oiled with a good-quality machine oil to reduce friction and wear and tear. The above care of machines increases their life.

Question 36.
Select the correct statement :
(a) A wheel barrow is a lever of class I.
(b) The efficiency of a machine is always 100%
(c) Friction in moving parts of a machine reduces its efficiency.
(d) No lever has the mechanical advantage greater than 1.
(e) It is easier to lift a load vertically up than to push it along an inclined plane.
(f) A screw is made by two inclined planes placed together.
Answer:
(c) Friction in moving parts of a machine reduces its efficiency.

C. Numericals

Question 1.
In a machine an effort of 10 kgf is applied to lift a load of 100 kgf. What is its mechanical advantage ?
Answer:
Given,
Load = loo kgf
Effort = 10 kgf
Selina Concise Physics Class 6 ICSE Solutions Chapter 4 Simple Machines 21

Question 2.
The mechanical advantage of a machine is 5. How much load it can exert for the effort of 2 kgf ?
Answer:
Given,
Mechanical advantage = 5
Effort 2 kgf
Selina Concise Physics Class 6 ICSE Solutions Chapter 4 Simple Machines 22

Question 3.
The mechanical advantage of a machine is 2. It is used to raise a load of 15 kgf. What effort is needed ?
Answer:
Given,
Mechanical advantage = 2
Load = 15 Kgf
Selina Concise Physics Class 6 ICSE Solutions Chapter 4 Simple Machines 23

Question 4.
A lever of length 100 cm has effort of 15 kgf at a distance of 40 cm from the fulcrum at one end. What load can be applied at its other end ?
Answer:
Selina Concise Physics Class 6 ICSE Solutions Chapter 4 Simple Machines 24

Selina Concise Physics Class 6 ICSE Solutions Chapter 4 Simple Machines 25

Question 5.
In a lever, fulcrum is at one end at a distance of 30 cm from the load and effort is at the other end at a distance of 90 cm from the load. Find :
(a) the length of load arm,
(b) the length of effort arm, and
(c) the mechanical advantage of the lever.
Answer:
Selina Concise Physics Class 6 ICSE Solutions Chapter 4 Simple Machines 26

Selina Concise Chemistry Class 8 ICSE Solutions – Carbon and Its Compounds

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Selina Concise Chemistry Class 8 ICSE Solutions – Carbon and Its Compounds

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APlusTopper.com provides step by step solutions for Selina Concise ICSE Solutions for Class 8 Chemistry Chapter 9 Carbon and Its Compounds. You can download the Selina Concise Chemistry ICSE Solutions for Class 8 with Free PDF download option. Selina Publishers Concise Chemistry for Class 8 ICSE Solutions all questions are solved and explained by expert teachers as per ICSE board guidelines.

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Selina Concise ICSE Solutions for Class 8 Chemistry Chapter 9 Carbon and Its Compounds

Points to Remember:

  1. Carbon occurs in the earth’s crust in the free as well as in the combined state.
  2. In the free state, it occurs as coal, diamond and graphite.
  3. In the combined state, carbon occurs in atmosphere (CO2) natural gas, food nutrients and carbonates.
  4. Diamond is the hardest naturally occuring substance known.
  5. Fullerenes are discovered only recently.

Exercise – I

Question 1.
Fill in the blanks.

(a) Carbon is present in both living and non-living things.
(b) The tendency of an element to exist in two or more forms but in the same physical state is called Allotropy.
(c) Crystalline and non- crystalline are the two major crystalline allotropes of carbon.
(d) Diamond is the hardest substance that occurs naturally.
(e) The name ‘carbon’ is derived from the Latin word carbo.

Question 2.
Choose the correct alternative.

(a) In combined state, carbon occurs as
(i) coal
(ii) diamond
(iii) graphite
(iv) petroleum

(b) A crystalline form of carbon is
(i) lampblack
(ii) gas carbon
(iii) sugar
(iv) fullerene

(c) Graphite is not found in
(i) Bihar
(ii) Maharashtra
(iii) Orissa
(iv) Rajasthan

(d) Diamond is used for
(i) making the electrodes of electric furnaces.
(ii) making crucible for melting metals.
(iii) cutting and drilling rocks and glass.
(iv) making carbon brushes for electric motors.

(e) Carbon forms innumerable compounds because
(i) it has four electrons in its outermost shell.
(ii) it behaves as a metal as well as a non- metal.
(iii) carbon atoms can form long chains.
(iv) it combines with other elements to form covalent compounds.

Question 3.
Write ‘true’ or ‘false’ against the following statements.

(a) Carbon constitues 0.03% of the earth’s crust. – True
(b) Graphite is the purest form of carbon. – False
(c) Coloured diamonds are costlier than colourless and transparent diamonds. – False
(d) Graphite has layers of hexagonal carbon bondings. – True
(e) Diamond is insoluble in all solvents. – True.

Question 4.
Define the following terms:
(a) Allotropy (b) Carat
(c) Crystal (d) Catenation
Answer:
(a) Allotropy: Allotropy is defined as the phenomenon due to which an element exists in two or more forms in the same physical state with identical chemical properties but with different physical properties.

(b) Carat – The weight of diamond is expressed in carats [ 1 carat = 0.2 g]

(c) Crystal – A crystal is a homogeneous solid which particles (atoms, molecules or ions) are arranged in difinite pattern due to which they have definite geometrical shape with plane surfaces e.g. sugar and sodium chloride.

(d) Catenation – The large number of organic compounds is due to the ability of carbon atom to form long chains with other carbon atoms through the sharing of electrons. This unique property of carbon is known as catenation.
selina-concise-chemistry-class-8-icse-solutions-carbon-and-its-compounds-1

Question 5.
State the terms:

(a) Substances whose atoms or molecules are arranged in a definite pattern. – Crystals.
(b) Different forms of an element found in the same physical state. – Allotropy.
(c) The property by which atoms of an element link together to form long chain or ring compounds. – Catenation

Question 6.
Name the following:

(a) The hardest naturally occurring substance. – Diamond.
(b) A greyish black non- metal that is a good conductor of electricity. – Graphite.
(c) The third crystalline form of carbon. – Fullerenes.

Question 7.
Answer the following questions:
(a) Why is graphite a good conductor of electricity but not diamond?
(b) Why is diamond very hard?
(c) What are fullerenes? Name the most common fullerenes.
(d) What impurity is present in black diamond?
(e) Explain the softness of graphite with reference to its structure.
Answer:
(a) In a graphite molecule, one valence electron of each carbon atom remains free, Thus making graphite a good conductor of electricity. Whereas in diamond, they have no free mobile electron. Thats why diamond are bad conductor electricity.

(b) A diamond is a giant molecule. The number of valence electrons in carbon atom is four. As such each carbon atom is linked with four neighboring carbon atoms. Thus forming a rigid tetrahedral structure. It is the strong bonding’that makes diamond the hardest substance.

(c) Fullerenes: Fullerenes are the third crystalline form of carbon.
Though they were discovered only recently. They have.been found to exist in interstellar dust as well as in the geological formations of the earth.
Common fullerenes are C – 32, C – 50, C – 70 and C – 76

(d) Black diamonds have copper oxide present in them as impurity.

(e) In a graphite molecule of each carbon atoms is linked with three neighboring carbon atoms. Thus forming a hexagonal arrangement of atoms. These hexagonal grouping of carbon atoms are arranged as layers or sheets piled one the top of other. The layers are held together by weak forces such that they can slide over one another. That is why graphite is soft.

Question 8.
Give two uses of (a) graphite (b) diamond.
Answer:

(a) Uses of graphite:

  1. For making the electrodes of electric furnaces.
  2. For making crucibles for melting metals due to its high melting points.

(b) Uses of Diamond:

  1. Diamond is used in jewellery as a gem
  2. It is used for cutting and drilling rocks, glass,

Question 9.
Write three differences between graphite and diamond.
Answer:
Difference between diamond and graphite.

Diamond

  1. Pure diamond is colourless and transparent.
  2. It is the hardest naturally occurring substance.
  3. It has high density i.e. 3.5 g/cm3
  4. It is bad conduct of electricity.
  5. It bums in air at 900°C to form carbon dioxide.

Graphite

  1. Graphite is greyish black opaque and shiny.
  2. It is soft and greasy to touch.
  3. It has low density i.e. 2.39 g / cm3
  4. It is good conductor of electricity.
  5. It bums in air at 700° C to form carbon dioxide.

Exercise – II

Question 1.
Fill in the blanks:

(a) Charcoal is formed when charcoal is burnt in a limited supply of air.
(b) Coal is a amorphous form of carbon.
(c) Peat is the most inferior form of coal.
(d) Wood charcoal is a bad conductor of heat and electricity.
(e) lampblack is used in making black shoe polish.

Question 2.
Choose the correct alternative

(a) Anthracite is
(i) an inferior type of coal
(ii) a superior type of coal
(iii) a cheapest form of coal
(iv) none of above

(b) Destructive distillation of coal yields
(i) coal tar
(ii) coal gas
(iii) coke
(iv) all of the above

(c) Lamp black is
(i) an amorphous form of carbon
(ii) a crystalline form of carbon
(iii) a pure form of carbon
(iv) a cluster of carbon atoms

(d) The process by which decayed plants slowly convert into coal is called.
(i) petrification
(ii) carbonisation
(ii) carbonification
(iv) fermentation

(e) The purest form of the amorphous carbon is
(i) wood charcoal
(ii) sugar charcoal
(iii) bone charcoal
(iv) lampblack

Question 3.
Write ‘true’ or ‘false’ against the following statements:

(a) Charcoal is a good adsorbent. True
(b) Coke is obtained by destructive distillation of sugar. False
(c) Activated charcoal is a good conductor of electricity. False
(d) Wood charcoal is an important constituent of gun powder. True
(e) Coal gas is used in the preparation of artificial ferilizers. False.

Question 4.
Define the following:
(a) Carbonization
(b) Adsorption
(c) Bone black
Answer: 
(a) Carbonization: The process of the slow conversion of vegetable matter into carbon-rich substances is called carbonization.
(b) Adsorption: Adsorption is the property due to which a substance absorbs gases, liquids and solids on its surface.
(c) Bone black: The Carbon content of bone charcoal is separated by treating the latter with hydrchloride acid, which dissolves the calcium phosphate. Carbon is then filtered out of the solution and in this form it is called bone black.

Question 5.
Name the following:

(a) Substances whose atoms or molecules are not arranged in a geometrical pattern. – Amorphous
(b) The best variety of coal. – Bituminous
(c) The purest form of amorphous carbon. – Anthracite
(d) An amorphous form of carbon that contains about 98% carbon. – Anthracite
(e) Mixture of carbon monoxide and hydrogen. – Water gas.

Question 7.
Answer the following questions:
(a) What is destructive distillation? What are the products formed due to the destructive distillation of coal?
(b) Why is wood charcoal used in water filters and gas masks?
(c) How is wood charcoal made locally? What other substances are formed in the process.
(d) How many carbon atoms are there in Buckminster fullerenes?
Answer: 
(a) Destructive Distillation: When a substances is heated in the absence of air. The process is called destructive distillation.
Products formed are: Coke, Coal tar, Coal gas and ammonia solution

(b) Due to its high adsorbing capacity, wood charcoal is used as gas masks to adsorb harmful gases. Wood charcoal is porous, that is why it is used to filter water.

(c) Wood charcoal is prepared when wood is heated in a limited supply of air. Locally wood charcoal is prepared by piling logs of wood one above the other with a gap in the centre of the pile. The pile is covered with wet clay to prevent the entry of air. A few holes are left at the bottom of the pile. The wood is set on fire. After some time when fire dies out, wood charcoal is left behind. The other substances are -wood tar, pyroligneous acid and wood gas.
selina-concise-chemistry-class-8-icse-solutions-carbon-and-its-compounds-2

(d) 60 carbon atoms are arranged in spherical structure in Buck minster fullerences.

Question 7.
(a) Descirbe the formation of coal,
(b) Name four types of coal with percentage of carbon present in each, with uses.
Answer:
(a) Formation of coal:- The formation of coal took millions of years. Coal was formed by the bacterial decomposition of ancient vegetable matter hurried under successive layers of the earth. Under in action of high temperature and pressure, and in the abcence of air, the decayed vegetable matter converted into coal.
(b) Types of Coal:

  1. Peat: It is light brown in colour and contains only 50 – 60% carbon. It is the most inferior form of coal.
  2. Lignite: it contains more than 60% carbon. It is brown in colour and harder than peat.
  3. Bituminous: It has 90%, 80%, 70 – 75% carbon contents. Bituminous coal is the most common variety of coal and used as house hold coal.
  4. Anthracite: It is the purest variety of coal. Its carbon contents vary between 92 – 98%. It is hard, dense and black, difficultto ignite.

Uses of coal:

  1. Coal is used as both domestic and industrial fuel.
  2. It is used to prepare coke, coal gas and coal tar.

Question 9.
Name the products formed when:
(a) wood is burnt in the absence of air.
(b) bone is heated in the absence of air.
(c) diamond is burnt in air at 900°C.
(d) graphite is subjected to high pressure and 3000°C temperature.
Answer:
(a) Wood charcoal is formed when wood is burnt in limited supply of air.
(b) Bone charcaol, bone oil and organic compound pyridine.
(c) Carbon dioxide.
(d) Artificial diamond.

Question 9.
Give two uses for each of the following:
(a) coal
(b) coke
(c) wood charcoal
(d) sugar charcoal
(e) bone charcoal
(f) lampblack
Answer: 
(a) Uses of coal

  • It is used as both a domestic and an industrial fuel.
  • It is used to prepare coke, coal gas and coal tar.

(b) Uses of coke

  • Coke is used as a smokeless fuel, in smelting furnaces.
  • It is used in the manufacturing of water and producer gas.

(c) Uses of wood charcoal:

  • Wood charcoal is used as a fuel.
  • It is an important constituent of gun powder.

(d) Sugar charcoal:

  • Sugar charcoal is mostly used as a reducing agent.
  • It is used to decolourise coloured solutions.

(e) Bone charcoal:

  • It is extensively used to decolourise cane-sugar in the process of manufacturing sugar.
  • It is also used in the manufacture of large number of phosphorous compounds.

(f) Uses of lamp black:

  • It is used in making black shoe polish.
  • It is used in the manufacture of tyres and gun powder.

Question 10.
Give balanced equations for the following chemical reactions:
(a) wood charcoal and cone, nitric acid
(b) coke and steam
(c) wood charcoal and lead monoxide.
Answer:
selina-concise-chemistry-class-8-icse-solutions-carbon-and-its-compounds-3

Exercise – III

Question 1.
(a) Name the chemicals required for the preparation of carbon dioxide in the laboratory.
(b) How will you collect the gas ?
(c) Write the balanced chemical equation for the above reaction.
(d) Draw a labelled diagram for the preparation of CO2 in the laboratory.
(e) Why is sulphuric acid not used for the preparation of carbon dioxide in the laboratory ?
Answer:
(a) Calcium carbonate and dilute hydrochloric acid.
(b) By upward displacement of air.
(c) CaCO3 + 2HCl → CaCl2 + H2O + CO2.
(d) Laboratory preparation of carbon dioxide
selina-concise-chemistry-class-8-icse-solutions-carbon-and-its-compounds-4
(e) Dilute sulphuric acid reacts with calcium carbonate. But it is not used because the calcium sulphate which is formed during the reaction is insoluble in water. It covers the marble chips and stops the reaction.
selina-concise-chemistry-class-8-icse-solutions-carbon-and-its-compounds-5

Question 2.
Write the balanced chemical equations for the preparation of carbon dioxide by:
(a) heating calcium carbonate.
(b) the action of acetic acid on sodium bicarbonate.
(c) the action of dilute sulphuric acid on sodium bicarbonate.
Answer:
selina-concise-chemistry-class-8-icse-solutions-carbon-and-its-compounds-6

Question 3.
What happens when:
(a) a lit splinter is introduced into a jar containing carbon dioxide ?
(b) moist blue litmus paper is placed in a jar containing carbon dioxide ?
(c) carbon dioxide is passed through lime water first in small amounts and then in excess ?
(d) a baking mixture containing baking powder is heated?
(e) a soda water bottle is opened ?
Answer:
(a) Lit splinter extinguishes.
(b) Blue litmus paper turns red.
(c) When CO2 is passed through lime water in small amount, it turns milky, when passed in excess milkiness disappears.
(d) Carbon dioxide is formed.
(e) When the pressure is released the bottled gas escapes with a bristling effervescence that ads fizz to the drink.

Question 4.
Give reasons for the following:
(a) An excess of carbon dioxide increases the temperature of the earth.
(b) Soda acid and foam types of fire extinguisher are not used for extinguishing electrical fires.
(c) Solid carbon dioxide is used for refrigeration of food.
Answer:
(a) Excess of carbon dioxide increases the temperature of the earth. Due to rise in temperature ice in the polar regions may melt causing floods in coastal regions island.
(b) In both of these fire extinguishers, the solutions are prepared in water, which conducts electricity. As a result an electric shock might result, which might lead to short- circuiting and another fire.
(c) Solid carbon dioxide serves as a coolant and refrigeration for preserving food articles.

Question 5.
What is a fire extinguisher ? What is the substance used in the modern type of fire extinguishers ? How is it an improvement over the soda acid-type and the foam-type fire extinguishers ?
Answer:
Fire Extinguisher— Fire extinguishers are a device in which carbon dioxide is produced in different forms for use as the extinguishing agent. It is a modem type of fire extinguisher in which liquid carbon dioxide is stored in a steel cylinder under pressure. Soda-acid and foam types of extinguisher cannot be used for extinguishing fire as they prepared in water, which conducts electricity and there can be short circuiting, causing another fire.

Question 6.
Explain the term ‘green house effect’. How can it be both beneficial and harmful for life on earth ?
Answer:
Green house effect— The trapping of the earth’s radiated energy by carbon dioxide present in air, so as to keep the earth warm, is called ‘green house effect’.
Green house is beneficial because this principle is applied to grow plants in colder regions.
Carbon dioxide increases the temperature of atmosphere. Due to rise in temperature; ice in the polar regions may melt, causing floods. So it is harmful for life on earth.

Question 7.
What steps should be taken to balance carbon dioxide in the atmosphere ?
Answer:
As global warming will cause an unbalanced ecological system, serious efforts should be made to balance the percentage of carbon dioxide in the atmosphere. Some of these steps are:

  • Growing more trees and plants.
  • Using smokeless sources of energy like solar energy, biogas, etc.
  • Using filters in the chimneys of factories and power houses.

Question 8.
State three ways by which carbon dioxide gas is added into the atmosphere.
Answer:

  1. By planting more trees.
  2. By combustion of fuels
  3. By decay of dead animals, plants and plants products.

Exercise – IV

Question 1.
Fill in the blanks:

(a) Carbon monoxide is formed when carbon is burnt in a limited supply of air or oxygen.
(b) Carbon monoxide bums in air with a pale blue flame to form carbon dioxide.
(c) Carbon monoxide is a products of incomplete combustion.
(d) A mixture of 95% oxygen and 5% carbon dioxide is called carbogen
(e) Carbon dioxide is used as a reducing agent in the extraction of pure metals from their corresponding ores.

Question 2.
Match the following.
selina-concise-chemistry-class-8-icse-solutions-carbon-and-its-compounds-7

Question 3.
How is carbon monoxide gas formed?
Answer:
Mostly carbon monoxide is formed when a large amount of carbon or its compounds is burnt in a limited supply of air or oxygen.
selina-concise-chemistry-class-8-icse-solutions-carbon-and-its-compounds-8

Question 4.
State the poisonous nature of carbon monoxide?
Answer:
Carbon monoxide is highly poisonous gas. If air containing 0.5% carbon monoxide by volume is inhaled, death can result This is because carbon monoxide combines with the haemogloblin present in the blood cells of our body to form a stable compound called carboxyl-haemoglobin. This does not allow to absorb oxygen. Thus depriving our body cells of oxygen. This cause obsruction in respiration and causes death.

Question 5.
Give two uses of carbon monoxide.
Answer:
Uses of carbon monoxide:

  • Carbon monoxide is a strong reducing agent.
  • Carbon monoxide is used in the extraction of pure metals from their ores.

Question 6.
Why is carbon monoxide called silent killer ?
Answer:
Carbon monoxide is produced by burning coal or wood in a limited supply of air. Since the gas is colourless and a barely detectable smell, people do not feel it and it can be proved as a silent killer.

Question 7.
Explain the reducing action of carbon monoxide.
Answer:
Reducing action of carbon- monoxide: Carbon monoxide is a strong reducing agent. It reduces the oxides of the less active metals to their respective metals and itself gets oxidised to carbon dioxide.
selina-concise-chemistry-class-8-icse-solutions-carbon-and-its-compounds-9

Question 8.
Write two remedies for carbon monoxide poisoning.
Answer:

  1. The victim should immediately brought out into the open.
  2. The victim should be given artificial respiration with caibogen.

Question 9.
Complete the reactions and balance them.
(a) CuO + CO →
(b) Fe2O2 + CO →
Answer:
selina-concise-chemistry-class-8-icse-solutions-carbon-and-its-compounds-10

ICSE Solutions for Class 6 Geography Voyage – Minerals and Ores

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ICSE Solutions for Class 6 Geography Voyage – Minerals and Ores

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APlusTopper.com provides step by step solutions for ICSE Solutions for Class 6 Geography Voyage. You can download the Voyage Geography ICSE Solutions for Class 6 with Free PDF download option. Geography Voyage for Class 6 ICSE Solutions all questions are solved and explained by expert teachers as per ICSE board guidelines.

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POINTS TO REMEMBER

  • Minerals are substances that are naturally present in the earth and are not formed from animal or vegetable matter.
  • An ore is a naturally occurring solid material from which a mineral, generally a metal, can be profitably extracted.
  • Minerals are generally classified as metallic and non-metallic minerals.
  • Metallic minerals include iron ore, uranium, bauxite, manganese, gold, silver and copper.
  • Non-metallic minerals include limestone, mica, coal and petroleum.
  • Mining is the process of taking out minerals and other substances from the earth.
  • There are two types of mining—surface mining and underground mining.
  • It is important to conserve minerals as they take thousands of years to form.

IMPORTANT TERMS

Ferrous minerals : Minerals which contain iron, such as iron ore, manganese and chrome.
Non – ferrous minerals : Minerals that do not contain iron, such as gold, silver, copper and lead.
Ore : A naturally occurring solid material from which a particular mineral, usually a metal, can be profitably extracted.

THINK AND ANSWER

How would our life be affected if coal, petroleum and natural gas were exhausted in the next 30 years ?
Answer:
If all the exhaustible natural resources are exhausted by human activities, then the survival of living beings would not be possible. Actually, fossil fuels are the most important source of energy for us today.
They are concentrated source of energy and give offheat and light on burning. The heat can be used to cook food or to run engines such as automobile engines. It can be used to generate electricity as in powerhouse where the most common fuel used is coal. Everything will not be available.

VALUES AND LIFE SKILLS

Conventional energy resources—coal and petroleum— are very important for a country. Therefore, we need to be careful while using them.
Can you suggest some ways by which we can reduce the use of conventional energy resources ?
Answer:

  1. Use more energy efficient by using energy saver products like LED lights etc.
  2. Use Bicycles for shorter distances instead of cars or bikes.
  3. Switch off the lights when not required.

EXERCISES

A. Fill in the blanks

  1. All rocks are composed of minerals.
  2. Minerals are obtained by a process called mining.
  3. Metallic minerals are generally found in igneous rocks.
  4. Ferrous minerals contain iron.
  5. Peat has very little carbon.

B. Write true or false

1. Metals can be profitably extracted from ores.
Answer. True.

2. Metallic minerals are generally found in sedimentary rocks.
Answer. False.
Correct — Metallic minerals are generally found in igneous rocks.

3. Bauxite is the lightest metal.
Answer. True.

4. Bituminous coal has the highest carbon content.
Ans. False.
Correct — Anthracite coal has the highest carbon content.

5. Mica is a metallic mineral.
Ans. False.
Correct— Mica is a non-metallic mineral.

C. Match the columns
ICSE Solutions for Class 6 Geography Voyage Chapter 7 Minerals and Ores 1
Answer:
ICSE Solutions for Class 6 Geography Voyage Chapter 7 Minerals and Ores 2
ICSE Solutions for Class 6 Geography Voyage Chapter 7 Minerals and Ores 3

D. Answer the following questions in brief:

Question 1.
What is a mineral ?
Answer:
Minerals are substances that are naturally present in the earth and are not formed from animal or vegetable matter.

Question 2.
Name a few minerals.
Answer:
Diamonds, quartz, topaz, gypsum, iron, copper, bauxite, zinc, gold, silver, manganese, etc.

Question 3.
What is an ore ?
Answer:
An ore is a naturally occurring solid material that contains a large amount of a particular material, using a metal which can profitably extracted, eg. iron ores, copper ores, bauxite (from which aluminium is extracted) zinc, etc.

Question 4.
What is the main difference between a ferrous and a non- ferrous mineral ?
Answer:
Ferrous minerals :

  1. These minerals contain iron.
  2. They have high tensile strength.
  3. Examples: Iron ore, manganese and chrome.

Non-ferrous minerals :

  1. These minerals does not contain iron.
  2. They have low tensile strength.
  3. Examples: Gold, silver, copper and lead.

Question 5.
Mention any two characteristics of iron ore.
Answer:
The most important mineral in the world is iron ore. It is known for its hardness, strength and ductility (it can be made or stretched into a thin wire).

Question 6.
Mention the different types of iron ore.
Answer:
There are four different types of iron ores-haematite, magnetite, limoniteandsiderite.

Question 7.
What is surface mining ?
Answer:
When the top layer of soil is removed and the rocks that lie underneath are extracted with the help of heavy machinery is called surface mining. Surface mining is done to extract minerals that are found close to the surface such as coal and some kinds of sedimentary rocks like limestone and mica.

Question 8.
Mention any three uses of coal.
Answer:
Coal is used for various purposes like cooking, heating and producing electricity, and in various industries.

E. Answer the following questions in one or two paragraphs

Question 1.
Differentiate between metallic and non-metallic minerals.
Answer:
Metallic Minerals :

  1. These minerals contain metals, which are hard substances.
  2. These minerals found in igneous rocks.
  3. Examples: Iron ore, bauxtie, manganese and copper, etc.

Non-metallic Minerals :

  1. These minerals does not contain extractable metals.
  2. These minerals found in sedimentary rocks.
  3. Examples: Coal, potash, limestone, gypsum, mica, etc.

Question 2.
Give an account of iron ore production in the world.
Answer:
Iron is the main metal used for making steel, which is used in almost all industries. The main producers of iron are China (42%), Australia (22%), Brazil (10%), South Africa, etc. India produces about 4% of total iron ore. Main states in India are Odisha, MP, Jharkhand, AndhraPradesh, Tamil Nadu.

Question 3.
Give any three uses of copper.
Answer:
Uses of copper are :

  • Copper is mainly used in making electric and telephone wires.
  • It is also used in making pipes and coins.
  • Alloys such as brass and bronze are made using copper.

Question 4.
What are the two types of mining ? Elaborate on the differences between the two.
Answer:
The two types of mining are:

  1. Surface mining — It is the removal of top layer of soil and rocks, to extract the minerals lying underneath is called surface mining. Surface mining is done to extract minerals that are found close to the surface such as coal and some kinds of sedimentary rocks like limestone and mica.
  2. Underground mining — It is the one in which a shaft is dug which is long, narrow passage and vertically deep into the ground and then people or heavy machinery is sent down, the tunnels are blasted using dynamite to extract the minerals, eg. gold, silver, etc.
    In surface mining, the top layer of the soil is removed, large pits or holes are dug and the rocks that lie underneath are extracted with the help of heavy machinery. These pits are called open cast mines or quarries. Open cast mining is a common form of coal mining in India.
    In surface mining, trees and other natural vegetation are destroyed. Surface mining is done to extract minerals that are found close to the surface such as coal and some kinds of sedimentary rocks like limestone and mica.
    Underground mining: In underground mining, a shaft, which is a long, narrow passage, is dug vertically deep into the groud. People and machinery are then sent down through this shaft. Sometimes, after after descending into the shaft, tunnels are blasted into the earth with the help of dynamite. Then the men and machines move about through these tunnels to take out things such as coal, gold, silver, tin, lead and copper. Underground mining causes sinking of the land, underground water pollution and surface water pollution, among other things.

Question 5.
Describe the importance of minerals.
Answer:
Minerals play an important role in our daily lives. A number of things of our daily use such as door knobs, latches, window grills, utensils, etc. are made of minerals. Iron and its alloy, steel, is used in making bridges, buildings, and wide range of machines and tools, which have made our life simpler and easier. Copper wires are used in our electrical and electronic gadgets. Copper tools and utensils are also widely used. Gold and silver are used in making our jewellery. Aluminium extracted from bauxite is used to make aeroplanes, our fastest means of transport. Mica is used in electrical goods and limestone is used as cement in constructing houses and buildings.
Coal, petroleum and natural gas are important energy or power resources. Coal is used for various purposes like cooking, heating and producing electricity, and in various industries. Once petroleum is refined, we obtain different products such as petrol, diesel, kerosene, cooking gas, etc. Vehicles such as cars, trucks, trains, etc. run on petrol and diesel. Kerosene is used for cooking and other purposes. Products such as plastics and cosmetics are also made from petroleum. Natural gas is used as a fuel in cars, buses, etc. and hence are important for the agricultural sector as well.

Question 6.
Why is it important to conserve minerals ?
Answer:
Minerals are important for every country for its development and they need to be conserve because :

  1. Minerals are non-renewable resources which once used can’t be obtained again as it takes thousands of years to form.
  2. Workable minerals are in insufficient quantities (just 1 % of the earth’s crust)
  3. We are rapidly consuming mineral resources that requires millions of years to be renewed.
  4. Industry and agriculture depend upon minerals and the substances manufacture from them.

F. Picture study.
ICSE Solutions for Class 6 Geography Voyage Chapter 7 Minerals and Ores 4
Look at this picture of the inside of an iron and steel industry and answer the following questions

Question 1.
Which are the major producers of iron and steel in Asia?
Answer:
China produces almost 45 per cent of the total world production of Iron and Steel.

Question 2.
Which states in the south of India produce a large quantity of iron and steel ?
Answer:
Andhra Pradesh and Tamil Nadu are the major iron-producing states.

Selina Concise Physics Class 6 ICSE Solutions – Matter

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Selina Concise Physics Class 6 ICSE Solutions – Matter

ICSE SolutionsSelina ICSE SolutionsML Aggarwal Solutions

APlusTopper.com provides step by step solutions for Selina Concise ICSE Solutions for Class 6 Physics. You can download the Selina Concise Physics ICSE Solutions for Class 6 with Free PDF download option. Selina Publishers Concise Physics for Class 6 ICSE Solutions all questions are solved and explained by expert teachers as per ICSE board guidelines.

Selina Class 6 Physics ICSE SolutionsChemistryBiologyMathsGeographyHistory & Civics

Selina Concise ICSE Solutions for Class 6 Physics Chapter 1 Matter

Synposis

  •  Matter is the substance which occupies space and has mass.
  •  The three states of matter are
  1.  solid,
  2.  liquid
  3.  gas.
  •  Matter is composed of large number of molecules.
  •  A molecule is the smallest particle which can exist freely in nature by itself and it retains the properties of the substance.
  •  All molecules of a substance are identical, but the molecules of different substanes are different.
  •  A molecule is very small in size (10-10 m).
  •  The molecules are separated from each other with spaces called inter-molecular spacing.
  •  The molecules in a substance are held together by the forces acting between the molecules which are called the inter-molecular forces.
  •  The force of attraction between the molecules of the same sub¬stance is called the force of cohesion, while the force of attraction between the molecules of two different substances is called the force of adhesion.
  •  The forces of cohesion and adhesion are effective only when the separation between the molecules is 10-9 m. When the separation becomes more, they vanish.
  •  The molecules in a substance are not at rest, but they are con¬stantly in motion.
  •  In a solid, the molecules are rigid, the inter-molecular spacing is least, the inter-molecular forces are strongest and the molecules remain in their fixed positions. They vibrate to and fro about their mean positions, but they do not leave their positions, so a solid has a definite shape and a definite volume.
  •  In a liquid, the molecules are not rigid, the inter-molecular spacing is more than that in solids, the inter-molecular forces are weak and the molecules are free to move within the boundary of the liquid, so the liquid has a definite volume, but it does not have a definite shape.
  •  In gases, the molecules are not rigid, the inter-molecular spacing is more than that in solids and liquids, the inter-molecular forces are weakest and the molecules are free to move anywhere in space. So the gas has neither a definite volume nor a definite shape.

Activity – 2

Classify 20 objects around you as solids, liquids and gases

Solids : Ice, Aluminium, Silver, Calcium, Gold, Iron, Sodium, chloride, Sugar, Wood.

Liquids : Water, benzene, chloroform, oil, honey, glycerine, hydrochloric acid, alcohol, dettol.

Gases : Steam, Air, Oxygen, Hydrogen, Chlorine, Nitrogen, Ammonia, Helium, Argon.

Test yourself

A. Objective Questions

1. Write true or false for each statement

(a) The molecules of each substance are identical.
Answer. False

(b) The inter-molecular forces are effective at all distances between the two molecules.
Answer. False

(c) The molecules in a substance arc in random motion.
Answer. Tme

(d) In a gas, the molecules can move anywhere in space. .
Answer. Tme

(e) The liquids are less viscous than the gases.
Answer. False

2. Fill in the blanks

(a) All the molecules of a substance are identical.
(b) The inter-molecular spacing is least in solids more in liquids and still more in gases.
(c) The molecular motion in liquid and gas is in zig-zag path.
(d) In a solid, the molecules vibrate to and fro but they remain at their fixed positions.
(e) The inter-molecular forces are the weakest in gases.
(f) A solid exerts pressure downwards on its base.
(g) The gases are least dense.
(h) A solid is most rigid.

3. Select the correct alternative

(a) The diameter of a molecule is approximately

  1.  1 cm
  2.  10 cm
  3.  10-10 m
  4.  1 m

(b) The inter-molecular forces are strongest in

  1.  solids
  2.  liquids
  3.  gases
  4.  both (i) and (ii)

(c) The molecules

  1.  in solid, liquid and gas, move freely anywhere.
  2.  in a solid, move freely within its boundary.
  3.  in a liquid, move within its boundary.
  4.  in a gas, move only within its boundary.

(d) The solids are

  1.  more dense
  2.  less dense
  3.  least dense
  4.  highly compressible

(e) The inter-molecular forces in liquids are

  1.  as strong as in solids
  2.  stronger than in solids
  3.  weaker than in solids
  4.  weaker than in gases

4. Match the following columns
Selina Concise Physics Class 6 ICSE Solutions Chapter 1 Matter 1

Selina Concise Physics Class 6 ICSE Solutions Chapter 1 Matter 2

B. Short/Long answer questions

Question 1.
Define matter. What is its composition ?
Answer:
Matter is defined as anything which occupies space and has mass. It can be perceived by our sense of smell, touch, sight, hearing and taste.
Matter is composed of tiny particles known as atoms.

Question 2.
Name the three states of matter.
Answer:
The three states of matter are solids, liquids and gases.
Solids —A solid has a definite shape and definite volume.
Example – wood, stone, iron, ice etc.
Liquid —A liquid has a definite volume but not definite shape.
Example — water, juice, milk, oil, etc.
Gases —A gas neither has definite shape nor a definite volume.
Example – air, hydrogen, oxygen, water vapour etc.

Question 3.
What is a molecule ?
Answer:
The smallest unit of matter which can exist independently is called molecule.
Example: Oxygen molecule (O2) made up of two (O) atoms.

Question 4.
What is the approximate size of a molecule ?
Answer:
Matter is made up of molecules which are very small in size (~10-9 m).

Question 5.
One litre of water has 6.02 × 1026 molecules. Estimate the size of a molecule.
Answer:
The size of a particle (or molecule of matter is very small. 1 litre of water has 6.02 × 1026 molecules, so the volume of a particle of
Selina Concise Physics Class 6 ICSE Solutions Chapter 1 Matter 3
Thus the diameter of a water molecule is nearly 1.27 × 10-9 metre.

Question 6.
What do you mean by inter-molecular spacing ?
Answer:
Intermolecular space — The space between any two consecutive molecules of a substance is called intermolecular space

Question 7.
Describe a simple experiment to illustrate the existence of inter-molecular spacing.
Answer:
Take 100 ml of water in a measuring cylinder. Add 20 gram of salt in water gently and stir it well so as to dissolve the salt well in water. It is noticed that the level of water does not change. It shows that the particles of salt occupy spaces between the particles of water.
Selina Concise Physics Class 6 ICSE Solutions Chapter 1 Matter 4

Question 8.
What do you mean by inter-molecular forces ?
Answer:
Intermolecular force of attraction — The force of attraction between the molecules (like molecules or unlike molecules) is called intermolecular force of attraction.

Question 9.
What are the forces of cohesion and adhesion ?
Answer:
The force of attraction between the molecules of similar kind is called force of cohesion.
Example: The forces between water molecules.
This force of cohesion keep the molecules of the substance bind together.
The force of attraction between different types of molecules is called force of adhesion.
Example: When a glass filled with water is emptied some water I particles remain stuck to the glass due to the adhesion between water molecules and glass.

Question 10.
State three characteristics of molecules of matter.
Answer:
The particles of matter called molecules, have the following characteristics:

  1.  They are very small in size.
  2.  They have spaces between them.
  3.  They are in constant random motion.
  4.  They always attract each other.

Question 11.
State the approximate spacing between two molecules of a matter.
Answer:
The spacing between particles of a matter is called inter-molecular space.

Question 12.
How do the solids, liquids and gases differ in their following properties
(a) Size
(b) Shape
(c) Density
Answer:
Selina Concise Physics Class 6 ICSE Solutions Chapter 1 Matter 5

Question 13.
The molecules in a substance are in motion. What type of path do they follow ?
Answer:
The particles in a substance are not at rest (in motion),and they move randomly in all possible directions in a zig-zag Path

Question 14.
Describe a simple experiment to illustrate that molecules are not at rest, but they constantly move.
Answer:
Take a beaker. Fill it partly with water. Add some lycopodium powder in the beaker containing water. Stir the contents of the beaker with a glass rod. Take out few drops of this suspension on a glass plate. Place it on the table and illuminate it with a table lamp. Observe the glass plate through a microscope. It is found that the fine particles of lycopodium powder move rapidly in a random manner and their path is zig zag as shown in figure below.
Selina Concise Physics Class 6 ICSE Solutions Chapter 1 Matter 6

Question 15.
Write down five general properties of solids, liquids and gases.
Answer:
Solids:

  1.  The molecules here are very tightly packed having negligible or very less intermolecular space.
  2.  They have the strongest intermolecular force of attraction.
  3.  The molecules have very small vibration about their mean position i.e. small amplitude.
  4.  They have a definite shape and volume.
  5.  They are generally hard and rigid.
  6.  They are good conductors of heat.

Liquids:

  1.  Molecules are less tightly packed.
  2.  The intermolecular force of attraction is less than that of solids.
  3.  The molecules here can move from one place to another
  4.  Do not have any particular shape of their own and thus acquire the shape of the vessel.
  5.  A particular quantity of a liquid has a definite volume at a given temperature.

Gases :

  1.  The force of attraction between the molecules is the least.
  2.  The intermolecular space is the largest.
  3.  Neither have a definite shape nor a definite volume.
  4.  The molecules move independently.
  5.  Worst conductors of heat.

Question 16.
Give the molecular model for a solid and use it to explain why a solid has a definite volume and a definite shape.
Answer:
Selina Concise Physics Class 6 ICSE Solutions Chapter 1 Matter 7
Here the molecules are very tighty packed that there is no or very less intermolecular space and there is high intermolecular force of attraction (force of cohesion).
The molecules do not move about their mean position and thus solids have a definite shape and volume.

Question 17.
Describe the molecular modcl for a liquid. I-low does it explain that a liquid has no definite shape, but has a definite Volume ?
Answer:
Selina Concise Physics Class 6 ICSE Solutions Chapter 1 Matter 8
Here the molecules are less tightly packed as compared to solids and also there is lesser force of intermolecular attraction. The intermolecular distance is greater than that in the solids. Thus, they do not have a definite shape but acquire the shape of the vessel in which they are contained but have a definite volume at a given temperature.

Question 18.
A gas has neither a definite volume nor a definite shape. Describe the molecular model to explain it.
Answer:
Here the molecules are far apart from each other i.e. have the greatest intermolecular distance which result into the weakest intermolecular forces of attraction. The molecules as are not
Selina Concise Physics Class 6 ICSE Solutions Chapter 1 Matter 9
bound by any strong force move about freely and thus gases do not have a definite shape and also do not have any definite volume.

Question 19.
Distinguish between the three states of matter—solid, liquid and gas on the basis of their molecular models.
Answer:
Solids:
Selina Concise Physics Class 6 ICSE Solutions Chapter 1 Matter 10
Here the molecules are very tighty packed that there is no or very less inteimolecular space and there is high intermolecular force of attraction (force of cohesion).
The molecules do not move about their mean position and thus solids have a definite shape and volume.
Liquids:
Selina Concise Physics Class 6 ICSE Solutions Chapter 1 Matter 11
Here the molecules are less tightly packed as compared to solids and also there is lesser force of intermolecular attraction. The intermolecular distance is greater than that in the solids. Thus, they donot have a definite shape but acquire the shape of the vessel in which they are contained but have a definite volume at a given temperature.
Gases :
Selina Concise Physics Class 6 ICSE Solutions Chapter 1 Matter 12
Here the molecules are far apart from each other i.e. have the greatest intermolecular distance which result into the weakest intermolecular forces of attraction. The molecules as are not bound by any strong force move about freely and thus gases do not have a definite shape and also do not have any definite volume.

Question 20.
Distinguish between solids, liquids and gases on the basis of their following properties :
(a) compressibility
(b) fluidity
(c) rigidity
(d) expansion on heating
Answer:
Selina Concise Physics Class 6 ICSE Solutions Chapter 1 Matter 13

Question 21.
What do you mean by the change of state of matter ? Explain:
(a) the change of a solid into a liquid at a constant temperature, and
(b) the change of a liquid into a gas at a constant temperature.
Answer:
The change in state of matter of a substance from solid to liquid or from liquid to gas is brought by imparting heat energy to it at a constant temperature.
(a) The process of change of a substance from solid state into its liquid state on absorption of heat at a particular temperature, called the melting point, is called melting or fusion i. e.
Selina Concise Physics Class 6 ICSE Solutions Chapter 1 Matter 14
(b) The process of change of a substance from a liquid state to its gaseous state at a particular temperature, called the boiling point,
is called boiling or vaporisation, i.e.
Selina Concise Physics Class 6 ICSE Solutions Chapter 1 Matter 15

ICSE Solutions for Class 8 Geography Voyage – Asia — Location, Extent, Political and Physical Features

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ICSE Solutions for Class 8 Geography Voyage – Asia — Location, Extent, Political and Physical Features

ICSE SolutionsSelina ICSE SolutionsML Aggarwal Solutions

ICSE Solutions Class 8 GeographyHistory & CivicsBiologyChemistryPhysicsMaths

Exercises

A. Fill in the blanks

  1. A mountain range in South-west Asia that separates Asia from Europe : Caucasus mountains.
  2. I am a plain formed by the rivers Ob, Yenisei, and Lena :Great Siberian Plain or Northern Lowlands.
  3. An area of inland drainage into which the Amu Darya and, Syr Darya drain : Turan Plain.
  4. I am a small zone from which several mountain ranges appear to radiate out: Pamir Knot.
  5. A plateau that lies between the Alborz and Zagros mountain ranges : Plateau of Iran.

B. Match the following

ICSE Solutions for Class 8 Geography Voyage Chapter 7 Asia - Location, Extent, Political and Physical Features 1
Answer:

ICSE Solutions for Class 8 Geography Voyage Chapter 7 Asia - Location, Extent, Political and Physical Features 2

C. State whether the following are true or false

1. Together with Europe, Asia is often referred to as Eurasia.
Answer. True.

2. Most of the Asian countries gained independence only after World War I.
Answer. False.
Most of the Asian countries gained independence only after World War II.

3. Three rivers which flow northwards into the Arctic Ocean are the Ganga, the Brahmaputra and the Yamuna.
Answer. False.
Three rivers which flow northwards into the Arctic Ocean are the Ob, the Yenisei and the Lena.

4. The Karakoram Range is a short range, which extends south-eastwards from the Pamir Knot between the Kunlun and the Himalayas.
Answer. True.

5. The Deccan Plateau of India lies between the Western Ghats and the Eastern Ghats.
Answer. True.

D. Answer the following questions in brief

Question 1.
Name the geographical features that border Asia in the north, south, east, and west.
Answer:
To the West of Asia are Ural mountains and the Caspian Sea. To the South-West are the Caucasus Mountains. To the North of Asia lies Arctic Ocean. To East lies the Pacific Ocean and to the south of Asia is Indian Ocean.

Question 2.
What do you understand by the term ‘archipelago ? Give two examples from the Pacific Ocean.
Answer:
Archipelago means a group of islands. Two examples in the Pacific Ocean are Japan and Philippines.

Question 3.
Name the rivers of the Great Siberian Plain.
Answer:
Rivers Ob, Yenisei and Lena have together built the Great Siberian Plain.

Question 4.
What kind of plateau is the Plateau of Tibet ?
Answer:
The Plateau of Tibet is an inter-mountain plateau, i.e., a plateau located between mountain ranges. It lies between the Kunlun and the Himalayas. The Plateau of Tibet, is also called the ‘Roof of the World’ as it is the highest flat land in the world.

Question 5.
In which country of Asia are the Mesopotamian plains situated ?
Answer:
The Mesopotanian plains are situated in Iraq.

E. Answer the following questions in detail

Question 1.
Describe the location of Asia.
Answer:
Asia lies almost wholly in the northern and eastern hemisphere. It is separated from Europe by the Ural Mountains and the Caspian Sea in the west and the Caucasus Mountain in the South-West. The Arctic Ocean lies to the north of Asia, the Pacific Ocean to the east and the Indian Ocean to the South of Asia.
Latitudinally, Asia extends from 10°S to 80°N, (8690 km). It east-west extent is 9,700 km, from 25°E to about 170°W. There are 48 independent countries in Asia. They vary in size from Russia, China and India which are the largest to Singapore, the Maldives and Bahrain which are the smallest. Some countries consist of group of islands like Japan, Philippines and Indonesia.

Question 2.
Describe the Northern Lowlands of Asia.
Answer:
The Northern Lowlands of Asia extend from the Ural Mountains in the west up to the Bering Strait in the north-east. These lowlands are traingular in shape and widest in the west. Lying between the Arctic Ocean in the north and the Central Mountains in the south,they form the world’s greatest continuous plains. Three rivers which flow northwards into the Arctic Ocean — Ob, Yenisey and Lena, have together built this plain. These marshy and swampy lowlands are also called as the Great Siberian plain. The lower courses and mouths of the rivers freeze in winter. So, water coming from the upper courses in warmer latitudes spreads out over large part of the plains. Another low lying land exists south of the Siberian Plains in Central Asia called as the Turan Plain. This plain is an area of inland drainage and is drained by rivers AmuDarya and SyrDarya.

Question 3.
Explain why the Pami Knot is called so. Write briefly about the mountain ranges that radiate from the Pamir Knot.
Answer:
Pamir Knot is called so because many mountain ranges appear to radiate outwards in different directions from this small zone. To the east of the Pamir Knot extend the Kunlun mountains and to the north extend the Tien Shan mountains. The Himalayas emerge from the Pamir Knot towards south-east direction. The Karakoram Range extends south-eastwards from the Pamir Knot between the Kunlun and the Himalayas. To the west of the Pamir Knot lies the Hindu Kush Range
and to the south-west radiates the Sulaiman Range.

Question 4.
Write briefly about the Arabian Plateau and the Deccan Plateau.
Answer:
The Arabian Plateau in Asia is steeper in the west but gently slopes eastwards towards the Persian Gulf. It is a dry plateau as it is in the region of low rainfall and has no rivers. It grew in importance to the rest of the world after petroleum reserves were discovered here.
The Deccan Plateau of India lies between the Western Ghats and the Eastern Ghats. It is steeper and higher along the Arabian Sea in the west but slopes gently towards the Bay of Bengal in the east. A number of rivers flow across this plateau like Godawari, Indravati, Krishna, Kaveri.

Question 5.
Describe the river valleys of Asia.
Answer:
The snow-fed and perennial rivers from the mountains form the river valleys which are very fertile and densely populated. Some of the river valleys of Asia are :

  1. The Mesopotamian plains in Iraq consist of the land between the two rivers – Tigris and Euphrates.
  2. The Ganga – Brahmaputra plains spread across north India and Bangladesh. It is built by the rivers Ganga and Brahmaputra.
  3. Plains in China are built up by the three big rivers — Huang He, Chang Jiang and Si Kiang.
  4. The Manchurian Plain is formed by river Amur.
  5. Plains of Indo-China are formed by the rivers Mekong and Menam.
  6. Large plain in Myanmar is formed by river Irrawaddy.
  7. Plains of Pakistan and Punjab are built by the river Indus and its five tributaries.

F. Picture study
The mountain peak seen in the picture is the highest peak in the world.
ICSE Solutions for Class 8 Geography Voyage Chapter 7 Asia - Location, Extent, Political and Physical Features 3

Question 1.
What is the height of this peak ?
Answer:
8850 m

Question 2.
In which mountain range does it lie ?
Answer:
Himalayas

G Map study
On an outline map of Asia, mark and name the following

  1. Rivers — Amur, Ob, Chang Jiang
  2. Gulfs — Persian Gulf, Gulf of Martaban
  3. Straits — Bering Strait, Strait of Malacca
  4. Seas — Arabian Sea, Caspian Sea, Sea of Japan
  5. Oceans — Arctic, Pacific, Indian
  6. Mountain ranges — Himalayas, Urals, Hindukush
  7. Write ROOF OF THE WORLD and GREAT SIBERIAN PLAIN in appropriate places on the map.

Answer:

ICSE Solutions for Class 8 Geography Voyage Chapter 7 Asia - Location, Extent, Political and Physical Features 4

Extra Questions

Question 1.
What do you mean by Eurasia ?
Answer:
The land mass of Europe and Asia as a whole is called Eurasia. (Europe + Asia—Eurasia)

Question 2.
What are perennial rivers ?
Answer:
Perennial rivers are rivers that flow throughout the year, even in the dry season.

Question 3.
Name the five physical regions of Asia
Answer:
Asia is broadly divided into five physical regions

  1. The Northern Lowlands (The Great Siberian Plain)
  2. The Central Fold Mountains and Inter-mountane Plateaux.
  3. The Southern Plateaux
  4. The Great River Valleys
  5. The Island Chains

Question 4.
Which mountain range has some of the world’s highest peaks ?
Answer:
The Karakoram Range

Question 5.
Name the plateaux (plural of plateau) of the Southern Plateaux of Asia.
Answer:
The Southern Plateaux include the Arabian Plateau, the Deccan Plateau, the shan plateau and the Yunnan Plateau.

Question 6.
Name the rivers that have built the Great River Valleys of Asia.
Answer:
The Great River Valleys of Asia have been built by the rivers Tigeris, Euphrates, Indus, Ganga, Brahmaputra, Chao Phraya or Menam, Chang Jiang or Yangtze, Huang He and Si Kiang. Small Plains have been formed along the rivers Irrawaddy, Salween, MeKong and Amur.

Question 7.
Write a note on the Island Chains of Asia.
Answer:
A series of island chains lies to the east and south-east of mainland Asia forming archipelagoes (group of islands) in an arc shape. The islands from the tip of the Kamchatka Peninsula in the Pacific Ocean are the Kuril Islands, the Japanese Islands (Hokkaido, Honshu, Shikoku and Kyushu), the Rhyukyu Islands, the Philippines, and the Indonesian Islands. The Andaman and Nicobar Islands, Sri Lanka, the Maldives and the Lakshadweep Islands are in South Asia.

Question 8.
Which is the largest and the smallest country in Asia ?
Answer:
Largest country in Asia — Russia
Smallest country in Asia — The Maldives

Question 9.
Name the following (in Asia)

  1. Most industrialized country –
  2. Highest elevation
  3. Highest Plateau
  4. Lowest point
  5. Deepest sea
  6. Deepest lake
  7. Longest strait
  8. Coldest Place
  9. Warmest place
  10. Number of countries in Asia

Answer:

  1. Japan
  2. Mount Everest (8,850 m)
  3. The Plateau of Tibet (‘THE ROOF OF THE WORLD’)
  4. The Dead Sea (400 m below sea level)
  5. The South China Sea
  6. Lake Baikal
  7. The strait of Malacca
  8. Verkhoyansk, Russia (-70°C)
  9. Dasht-e Lut (Iran)
  10. 48

Question 10.
What are the six regional divisions of Asia ?
Answer:
The six regional divisions of Asia are :

  1. East Asia — It consists of China, North Korea, South Korea, Japan, Taiwan and Mongolia.
  2. North Russia — It includes the Asian part of Russia (Siberia and the Russian far East).
  3. Central Asia — It consists of several landlocked countries like Kazakhstan, Uzbekistan, Kyrgyztan, Tajikistan, Turkmenistan and Afghanistan.
  4. South-East Asia — The countries of South-East Asia fall into two different sections. The northern part consists of Vietnam, Laos, Cambodia, Thailand and Myanmar. The Southern part consists of the island countries of Malaysia, Singapore, Brunei, Indonesia, East Timor and the Philippines.
  5. South Asia — It consists of India, Pakistan, Nepal, Sri Lanka, Bhutan, Bangladesh and the island country of Maldives. ‘
  6. West Asia — It comprises of Armenia, UAE (United ArabEmirates), Yemen, Azerbaijan, Bahrain, Lebanon, Oman, Cyprus, Syria, Turkey, Georgia, Iran, Israel, Jordan, Kuwait, Qatar and Saudi Arabia.

Question 11.
Name some important cities of East Asia.
Answer:
East Asia has some of the world’s busiest cities such as Tokyo, Beijing, Shanghai and Hong Kong.

Question 12.
Which are the two main rivers of Central Asia and why are they important ?
Answer:
The two main rivers of the Central Asia are the Amu Darya and the Syr Darya. The rivers are very important to the Central Asian countries as the region remains quite dry for most of the year. 60% of Central Asia is deserts.

Question 13.
Write a short note on South Asia.
Answer:
South Asia refers to the Southern Asian countries of India, Pakistan, Nepal, SriLanka, Bhutan, Bangladesh and the island country of Maldives. This region is home to about one fifth of the world’s population and is the most densely population region in the world. It is bounded in the north by the Himalayan mountains, to the east by the Bay of Bengal, to the West by the Arabian Sea and to the South by the Indian Ocean. South Asia has a wide variety of natural vegetation and wildlife.

Question 14.
Why is West Asia not densely populated ?
Answer:
West Asia is not densely populated because of its inhospitable climate.

Question 15.
Why is the Plateau of Tibet called the ‘Roof of the World’?
Answer:
The Plateau of Tibet is called the ‘Roof of the World’ as it is the highest flat land in the world at an average height of 4,880 m above sea level.

Question 16.
Which is the highest and the second highest peak in the world and where are they situated ?
Answer:
Mt. Everest (8,850 m) in the Himalayas is the highest peak in the world and Mt K2 or Godwin Austin (8,611 m) in the Karakoram Range is the world’s second highest peak.

Question 17.
Name few glaciers found in Himalayas and Karakoram range of mountains.
Answer:
Siachen glacier Baltoro glacier

Question 18.
Name few passes in the Central Fold Mountains and Inter – Montane Plateaux which allow the movements of goods and people across the mountains.
Answer:
Khyber pass, Bolan pass and Solan pass.

Question 19.
Why did the Arabian Plateau become important to the rest of the world ?
Answer:
The Arabian Plateau became important to the rest of the world after petroleum reserves were discovered here in the 20th century.

Question 20.
Why are the fertile river valleys and plains of Asia and such as the Mesopotamian Plains, the Indo-Gangetic Plains and the Great Plains of China called the cradles of civilization ?
Answer:
This is because the earliest civilization developed along these river banks.

Question 21.
What makes Asia a continent of contrasts ?
Answer:
The outstanding feature of the geography of Asia is the great variety and diversity in physical, cultural and economic characteristics. This makes it a continent of contrasts.

22. Fill in the blanks

  1. Asia lies wholly in the northern and eastern hemispheres.
  2. Together with Europe, Asia is called as Eurasia.
  3. Pacific Ocean lies to the east and Indian Ocean to the south of Asia.
  4. There is a time difference about 11 hours between the Anatolian Plateau (Asia Minor) in the west and the Pacific Coast in the east of Asia.
  5. There are 48 independent countries in Asia.
  6. Asia is the largest continent in the world.
  7. Asia occupies one-third of the total land area and three-fifths of the total population of the world.
  8. USSR broke up into several independent republics in 1991, some of which are in Europe and some in Asia now.
  9. North Asia is divided by a long mountain range known as the Ural Mountains.
  10. Siberia lies in the East of Ural Mountains.
  11. The two main rivers of Central Asia are the Amu Darya and the SyrDarya.
  12. South Asia is the most densely populated region in the world.
  13. The Northern Lowlands (the Great Siberian Plain) are the world’s greatest continuous plains.
  14. The Himalayas emerge from the Pamir Knot in south-east direction.
  15. Mt Everest, the world’s highest peak lies on the border between Nepal and the Tibet Autonomous Region of China.
  16. The Arabian Plateau is a dry plateau as it is in the region of low rainfall and no rivers.
  17. Punjab is also called as the land of five rivers.
  18. The Chang Jiang (Yangtze) is Asia’s longest river.
  19. The Lakshadweep Islands and the Andaman and Nicobar Islands are in South Asia.
  20. The Maldives is the smallest country in Asia.
  21. The zone from where the mountain ranges appear to radiate outwards in different directions in the Central Fold mountains in Asia is called Pamir Knot.