Question

The percentage of carbon dioxide in air is

• A. 78%
• B. 21%
• C. 0.9%
• D. 0.03%

Answer 1

The correct option is D

0.03%

Air is a mixture of gases that forms a layer called the atmosphere around the earth's surface.

explanation of correct option-

(D) 0.03%

The composition of carbon dioxide (CO₂) in the air varies from 0.03% to 0.04% and it can be higher in industrial and urban areas.

Explanation of incorrect options-

(A) 78% - It is the percentage composition of nitrogen (N) in the air.

(B) 21% - It is the percentage composition of oxygen (O) in the air.

(C) 0.9% - It is the percentage composition of argon (Ar) in the air. Argon is a noble gas

Thus, the percentage of carbon dioxide in the air is 0.03%.

Hence, option (D) is correct.