With reference to “water vapour”, which of the following statements is/are correct?

Question

1. It is a gas, the amount of which decreases with altitude.

2. Its percentage is maximum at the poles.

Select the answer using the code given below:

(a) 1 only
(b) 2 only
(c) Both 1 and 2
(d) Neither 1 nor 2

Answer 1

(a) 1 only

Explanation:

• Statement 1: Correct. Water vapour is indeed a gas and its concentration decreases with altitude. The air becomes colder and less capable of holding moisture as altitude increases, leading to a decrease in water vapour.

• Statement 2: Incorrect. The percentage of water vapour is not maximum at the poles. In fact, it is generally very low at the poles due to the cold temperatures, which limit the air's capacity to hold moisture. Water vapour is more abundant in warm, tropical regions.

Therefore, only statement 1 is correct, making option (a) the correct answer.