Fill in the blanks:

(a) The layer of air around the earth is called the …………… .

(b) Although we cannot see air, we can …………… it.

(c) Air is a …………… of gases.

(d) Plants and animals maintain the balance of …………… and …………… in air.

(e) Polluted air is …………… for health.

(f) The supporter of combustion in air is …………… .

(g) Green plants need …………… to prepare food.

(h) Oxygen is used in …………… of the food to get …………… .

(i) Aquatic plants and animals use …………… in water.

(j) The reddish brown powder on the surface of iron nails exposed to air and moisture is called …………… .

Write 'true' or 'false' for the following:

(a) Air is a compound. ……………

(b) Carbon dioxide is given out during photosynthesis. ……………

(c) Respiration needs nitrogen. ……………

(d) The composition of air was discovered by Lavoisier. ……………

(e) The major component of air is oxygen. ……………

What is air pollution ?

Name two air pollutants which

(a) affect our health,

(b) cause acid rain,

(c) cause global warming.