How many electrons does an oxygen atom need to gain in order to achieve a stable, noble gas electron configuration?

• A. 1
• B. 2
• C. 8
• D. 4

Answer: (B)

Verified step by step guidance

1. Identify the atomic number of oxygen, which is 8. This means an oxygen atom has 8 protons and, in its neutral state, 8 electrons.
2. Recall that a stable, noble gas electron configuration means having a full outer electron shell, typically an octet (8 electrons) in the valence shell for main group elements like oxygen.
3. Determine the electron configuration of oxygen: 1s\^2 2s\^2 2p\^4. The valence shell (second shell) has 6 electrons (2 in 2s and 4 in 2p).
4. Calculate how many electrons oxygen needs to gain to complete its octet: since it has 6 valence electrons, it needs 8 - 6 = 2 more electrons.
5. Conclude that oxygen must gain 2 electrons to achieve the electron configuration of the nearest noble gas, neon.