Question

which is the electronic configuration for oxygen?
1s² 2s² 2p¹
1s² 2s² 2p³
1s² 2s² 2p⁴
1s² 2s² 2p⁶

Explanation:

Step1: Determine the atomic number of oxygen

The atomic number of oxygen is \(Z = 8\). This means an oxygen atom has 8 electrons.

Step2: Fill the orbitals according to the Aufbau principle

• The \(1s\) orbital can hold a maximum of 2 electrons. So, after filling \(1s\), we have \(1s^{2}\) and \(8 - 2=6\) electrons left.
• The \(2s\) orbital can hold a maximum of 2 electrons. After filling \(2s\), we have \(2s^{2}\) and \(6 - 2 = 4\) electrons left.
• The remaining 4 electrons go into the \(2p\) orbital. So, the electronic configuration is \(1s^{2}2s^{2}2p^{4}\).

Answer:

\(1s^{2}2s^{2}2p^{4}\) (the third option)