Question

Arrange the following gases in descending order in terms of percentage in dry air of the lower atmosphere:
• [(A)] Carbon dioxide
• [(B)] Argon
• [(C)] Nitrogen
• [(D)] Oxygen Choose the correct answer from the options given below:

• A. D, C, A, B
• B. C, A, D, B
• C. C, D, A, B
• D. C, D, B, A

Hint:

Composition of dry air: \[ \mathrm{Nitrogen \approx 78%} \] \[ \mathrm{Oxygen \approx 21%} \] \[ \mathrm{Argon \approx 0.93%} \] \[ \mathrm{CO_2 \approx 0.04%} \]

Answer 1

The Correct Option is D

Step 1: Recall the composition of dry air.
Major gases present in dry air are: \[ \mathrm{Nitrogen \approx 78%} \] \[ \mathrm{Oxygen \approx 21%} \] \[ \mathrm{Argon \approx 0.93%} \] \[ \mathrm{Carbon\ Dioxide \approx 0.04%} \]

Step 2: Arrange in descending order.
Descending order means: \[ \mathrm{Highest \rightarrow Lowest} \] Thus: \[ \mathrm{Nitrogen > Oxygen > Argon > Carbon\ Dioxide} \] Using symbols: \[ C > D > B > A \]

Step 3: Identify the correct option.
Therefore: \[ \boxed{C,\ D,\ B,\ A} \] Hence, the correct answer is: \[ \boxed{\mathrm{(D)}} \]