Q.No. 1. How is our atmosphere different from the atmospheres on Venus and Mars ?
Answer:
Atmosphere of Earth has 79% nitrogen, 20% oxygen and a small amount of carbon dioxide, water vapour and other gases.
This existence of life is possible on Earth.
Whereas atmospheres of Venus and Mars have 95% - 97% carbon dioxide.
Existence of life is not possible.
Q.No. 2. How does the atmosphere act as a blanket ?
Answer:
Air is bad conductor of heat. The atmosphere keeps the average temperature of the Earth fairly constant during the day and even during the course of the whole year such as blanket.
The atmosphere prevents the sudden increase and decrease of temperature during the daylight hours and the night just like blanket.
The atmosphere slows down the escape of heat into outer space.
Due to following behavior of atmosphere acts as blanket.
Q.No. 3. What causes winds ?
Answer:
The movement of air causes winds. When air is heated by radiation from the heated land or water, it rises. Land gets heated faster than water. A region of low pressure is created. The movement of air from one region to the other region creates winds.
The rotation of Earth and presence of mountain ranges cause winds.
Q.No. 4. How are clouds formed ?
Answer
Water vapour moves from high pressure region to low pressure region.
A large amount of water evaporates and goes into air due to heating of water bodies. The hot air rises up carrying the water vapour with it. As the air rises, it expands and cools. This cooling causes the water vapour in the air to condense in the form of droplets.
This process forms the clouds.
Q.No. 5. List any three human activities that you think would lead to air pollution.
Answer
There are following human activities which lead to air pollution.
1. Burning of coal and petroleum.
2. Deforestation
3. Industrialization
Q.No. 6. Why do organisms need water ?
Answer
There are following reasons due to which organisms need water.
1. Usually, the reactions that take place in our body or within cells occur between substances that are dissolved in water. So, all cellular process need water.
2. Most of the substances are transported in a dissolved form, water is necessary.
Q.No. 7. What is the major source of water in the city/town/village where you live ?
Answer
River is the major source of fresh water.
Q.No. 8. Do you know any activity which may be polluting this water source ?
Answer
The discharge of waste water from homes, industries, hospitals, etc. into the river pollutes this fresh water source.
Class IX
NCERT Text Book
Questions Answers
Answer:
Atmosphere of Earth has 79% nitrogen, 20% oxygen and a small amount of carbon dioxide, water vapour and other gases.
This existence of life is possible on Earth.
Whereas atmospheres of Venus and Mars have 95% - 97% carbon dioxide.
Existence of life is not possible.
Q.No. 2. How does the atmosphere act as a blanket ?
Answer:
Air is bad conductor of heat. The atmosphere keeps the average temperature of the Earth fairly constant during the day and even during the course of the whole year such as blanket.
The atmosphere prevents the sudden increase and decrease of temperature during the daylight hours and the night just like blanket.
The atmosphere slows down the escape of heat into outer space.
Due to following behavior of atmosphere acts as blanket.
Q.No. 3. What causes winds ?
Answer:
The movement of air causes winds. When air is heated by radiation from the heated land or water, it rises. Land gets heated faster than water. A region of low pressure is created. The movement of air from one region to the other region creates winds.
The rotation of Earth and presence of mountain ranges cause winds.
Q.No. 4. How are clouds formed ?
Answer
Water vapour moves from high pressure region to low pressure region.
A large amount of water evaporates and goes into air due to heating of water bodies. The hot air rises up carrying the water vapour with it. As the air rises, it expands and cools. This cooling causes the water vapour in the air to condense in the form of droplets.
This process forms the clouds.
Q.No. 5. List any three human activities that you think would lead to air pollution.
Answer
There are following human activities which lead to air pollution.
1. Burning of coal and petroleum.
2. Deforestation
3. Industrialization
Q.No. 6. Why do organisms need water ?
Answer
There are following reasons due to which organisms need water.
1. Usually, the reactions that take place in our body or within cells occur between substances that are dissolved in water. So, all cellular process need water.
2. Most of the substances are transported in a dissolved form, water is necessary.
Q.No. 7. What is the major source of water in the city/town/village where you live ?
Answer
River is the major source of fresh water.
Q.No. 8. Do you know any activity which may be polluting this water source ?
Answer
The discharge of waste water from homes, industries, hospitals, etc. into the river pollutes this fresh water source.
No comments:
Post a Comment