1s² 2s² 2p⁶ 3s² 3p³

Here's a breakdown:

* 1s²: The first energy level (n=1) has two electrons in the 's' subshell.

* 2s²: The second energy level (n=2) has two electrons in the 's' subshell.

* 2p⁶: The second energy level (n=2) has six electrons in the 'p' subshell.

* 3s²: The third energy level (n=3) has two electrons in the 's' subshell.

* 3p³: The third energy level (n=3) has three electrons in the 'p' subshell.

Important Note: This is the ground state electron configuration. Phosphorus can also exist in excited states where electrons occupy higher energy levels.