Question

what electron configuration matches an oxygen atom? 1 2 3 4 1s²2s²2p⁶ 1s²2s²2p⁶3s² 3p⁶4s²3d¹⁰4p⁵ 1s²2s²2p⁶3s²3p⁶4s²3d¹ 1s²2s²2p⁴

Explanation:

Step1: Determine the atomic number of oxygen

Oxygen has an atomic number \(Z = 8\).

Step2: Fill electrons according to Aufbau principle

• Fill \(1s\) first: \(1s\) can hold 2 electrons (\(1s^{2}\)).
• Then fill \(2s\): \(2s\) can hold 2 electrons (\(2s^{2}\)).
• Remaining electrons (\(8-(2 + 2)=4\)) go to \(2p\) ( \(2p\) can hold up to 6 electrons). So the electron configuration is \(1s^{2}2s^{2}2p^{4}\).

• Option 1 (\(1s^{2}2s^{2}2p^{6}\)) has 10 electrons (neon configuration).
• Option 2 (\(1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^{2}3d^{10}4p^{5}\)) has \(2 + 2+6 + 2+6 + 2+10 + 5=35\) electrons (bromine - like for neutral atom in a more complex configuration context).
• Option 3 (\(1s^{2}2s^{2}2p^{6}3s^{2}3p^{6}4s^{2}3d^{1}\)) has \(2+2 + 6+2+6+2 + 1=21\) electrons (scandium - like).

Answer:

1. \(1s^{2}2s^{2}2p^{4}\)