Find the odd one out. Sodium, Calcium, Iron, Oxygen

Question

Accepted Answer

1. Check metal vs non-metal.

2. Sodium is a metal (Na, $Z=11$). Calcium is a metal (Ca, $Z=20$). Iron is a metal (Fe, $Z=26$).

3. Oxygen is a non-metal gas (O, $Z=8$). It is different from the other three.

4. So the odd one out is **Oxygen**.

FINAL_ANSWER: b

Answer

Answer

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