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Atomic masses: identify the element with the smallest atomic mass among the given choices Compare standard atomic masses at natural isotopic abundance for Oxygen, Sulphur, Nitrogen, and Carbon. Choose the correct option.

Difficulty: Easy

Oxygen
Sulphur
Nitrogen
Carbon

Correct Answer: Carbon

Explanation:

Given data
Approximate standard atomic masses (u): O ≈ 16, S ≈ 32, N ≈ 14, C ≈ 12.

Concept/Approach
Atomic mass reflects the weighted average mass of naturally occurring isotopes. To find the minimum, compare the known approximate values.

Step-by-step check
Compare: 12 (C) < 14 (N) < 16 (O) < 32 (S)

Common pitfalls
Do not confuse atomic number with atomic mass; also, sulphur's mass is roughly double oxygen's.

Final Answer
Carbon

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