Air Is Life

Q.

The layer of air surrounding the earth, which is a source of oxygen, is called ______.

Q.

Plants take carbon dioxide from the atmosphere mainly through their:

1. roots

2. stem

3. flower

4. leaves

Q.

How does the atmosphere act as a blanket?

Q.

Fractional distillation is used to separate crude oil.

1. False
2. True

Q.

Which is the most essential element of life?

1. Air

2. Water

3. Food

4. Shelter

Q.

Which gas is put in the bubble sheet?

Q. During photosynthesis plants give out .

1. oxygen
2. nitrogen
3. carbon dioxide

Q. Pooja fixed a candle at the bottom of the container holding water. After lighting the candle, she inverted a glass jar over it. What do you think she observed?

1. The flame continued to burn, and water rose in the jar.
2. The flame was put off, and black smoke got deposited on the sides of the jar.
3. The flame continued to burn, and molten wax felt into the water.
4. The flame was put off and water rose in the jar.

Q.

State three differences between water and air.

Q.

Plant takes carbon dioxide from air through tiny openings found in the:

1. Fruit

2. Leaves

3. Root

4. Stem

Q.

Air is a mixture, not a compound.

1. True

2. False

Q. Pick the factor which does not affect photosynthesis.

1. Light Intensity
2. The availability of carbon dioxide
3. Animals
4. Water

Q. During rainy season, animals living in the soil come out of their holes for __________.

1. excretion
2. respiration
3. digestion
4. reproduction

Q. Name the solvent where sulphur and phosphorus get dissolved.

Q.

Why cant planes fly in the mesosphere ?

Q.

The technique ‘fractional distillation’ is based on the difference in the boiling points of the constituents of a mixture.

1. True
2. False

Q.

which places are air found?

1. Land

2. Space

3. Water

4. None of these

Q. Animals inhale gas A and exhale gas B. Gas A supports combustion. Gas B is used by plants to prepare their food. Identify gas A and gas B.

1. A: nitrogen, B: oxygen
2. A: oxygen, B: carbon dioxide
3. A: carbon dioxide, B: oxygen
4. A: oxygen, B: nitrogen

Q.

During photosynthesis plants take in ______ and release ______ .

Q.

Write a note on oxygen cycle.

Q. The products of petroleum are refined by the process of

1. Destructive distillation
2. Carbonification
3. Solidification
4. Fractional Distillation

Q. Warm air is heavier than cold air. State whether the above statement is true or false and explain.

1. True, because warm air contains more heat
2. True, because warm air molecules are separated by greater distances
3. False, because molecules of warm air expand and become less dense
4. False, because cold air contain extra temperature than hot air

Q.

Explain the following method of separation with an example each:

Fractional distillation

Q. Which of the following gases is/are heavier than dry air?

1. Moist nitrogen
2. Moist air
3. Oxygen
4. Hydrogen sulphide

Q.

Food synthesised by plants is stored as___.

Q.

Rashid went to an oil refinery and there he saw that crude oil is separated by various methods. Which of the following is the most suitable method to separate the components of crude oil?

1. Fractional distillation

2. Distillation

3. Chromatography

4. Evaporation

Q.

Question 3

How will you prove that air supports burning?

Q. The process of changing a gas or vapour into liquid is called ______.

Q.

In the distillation apparatus is there any reason for the two water outlets??

Q. Which of the following plays a major role in the formation of a thunderstorm?

1. Conduction
2. Convection
3. Radiation
4. All of these