Name the sources of carbon dioxide in air.

2

(a)

A gas is given to the patients having breathing problems. Which gas is it?

2

(a)

State one biological importance of air dissolved in water.

2

(a)

Oxygen is released by plants. How?

2

(a)

Policemen use the masks for what reason?

2

(a)

Oxygen and nitrogen form 99% of the air. Other 1% is constitute by which components?

2

(a)

Air can be used to generate electricity. How?

2

(a)

Carbon dioxide gas is used to extinguish fire. Give reason.

2

(a)

Do you know the reason why mountaineers carry oxygen cylinders with them?

2

(a)

How will you prove that air supports burning?

2

(a)

Why do you think mountaineers carry oxygen cylinders with them, while climbing high mountains?

2

(a)

How do aquatic animals take oxygen for respiration?

2

(a)

What is the composition of air?

2

(a)

Why do mountaineers carry oxygen cylinders with them?

2

(a)

Mention two uses of air.

2

(a)