Question

Answer the following.
A. What is pollution ?
B. What are pollutants ?
C. What is acid rain ?
D. What is green house effect ?
E. Which are visible pollutants known to you ?
F. Which are invisible pollutants ?

Answer 1

a. Pollution is any undesirable change that takes place in the environment which is harmful to both living and non-living things.

b. Pollutants are the harmful chemicals and substances that cause pollution. For example, nitrogen oxides, sulphur oxides, carbon monoxide, pesticides etc.

c. Gases such as sulphur dioxide, sulphur trioxide and nitrogen dioxide, when present in air, combine with the water droplets present in the atmosphere to form acid droplets. These droplets remain suspended in air and fall down on the earth along with rain, thereby making the rain acidic. Such rain is called acid rain.

d. The increase in the average temperature of the earth’s surface due to the increase in concentration of greenhouse gases such as carbon dioxide, methane, etc. is called greenhouse effect.

e. Pollutants which are visible to our naked eyes are called visible pollutants. For example, sewage, plant and animal wastes, pesticides, plastic, sand etc.

f. Invisible pollutants are pollutants which are not visible to our naked eyes. For example, fungi, viruses, bacteria, gases like carbon monoxide, nitrogen dioxide etc.