Question

In the composition of the atmosphere (% volume), arrange the following gases in ascending order. \[ \begin{aligned} A.&\ \text{Argon} B.&\ \text{Nitrogen} C.&\ \text{Carbon dioxide} D.&\ \text{Oxygen} \end{aligned} \] Choose the correct answer from the options given below:

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

Hint:

Atmospheric composition: \[ \boxed{ \mathrm{CO_2} < \mathrm{Ar} < \mathrm{O_2} < \mathrm{N_2} } \] Mnemonic: “CANO -- Carbon dioxide, Argon, Oxygen, Nitrogen.”

Answer 1

The Correct Option is B

Concept: The major atmospheric gases by volume are: \[ \begin{aligned} \text{Carbon dioxide} &\approx 0.04\%, \text{Argon} &\approx 0.93\%, \text{Oxygen} &\approx 20.95\%, \text{Nitrogen} &\approx 78.08\%. \end{aligned} \]

Step 1: Arrange from smallest to largest. \[ \boxed{ \text{Carbon dioxide} < \text{Argon} < \text{Oxygen} < \text{Nitrogen} } \]

Step 2: Convert into letters. \[ \boxed{ C \rightarrow A \rightarrow D \rightarrow B } \] Hence, \[ \boxed{\text{(B)}} \]