Question

Which of the following is true about air?
(i) Air is a mixture of several gases.
(ii) Air exerts pressure.
(iii) The composition of air is constant at all places.

• A. Only (i) and (ii)
• B. Only (ii) and (iii)
• C. Only (i) and (iii)
• D. (i), (ii) and (iii)

Answer 1

The correct option is A Only (i) and (ii)

Air is a mixture of several types of gases. It can exert pressure. The composition of air is not constant and changes from place to place. For example: in polluted areas, since emissions of carbon dioxide are very high, air over there contains a higher percentage of carbon dioxide.