What is the electron configuration of phosphorus

1s², 2s², 2p⁶, 3s², 3p⁵

Given

Phosphorus element

Required

The electron configuration

Solution

The energy level is expressed in the form of electron configurations.  

Writing electron configurations starts from the lowest to the highest sub-shell energy level. There are 4 sub-shells in the shell of an atom, namely s, p, d and f.

Charging electrons in the sub shell uses the following sequence:  

1s², 2s², 2p⁶, 3s², 3p⁶, 4s², 3d¹⁰, 4p⁶, 5s², 4d¹⁰, 5p⁶, 6s², etc.  

Electron configurations are based on the number of electrons in the atomic number.

The atomic number of the phosphorus is 15, so the number of electrons is 15.

The configuration:

1s², 2s², 2p⁶, 3s², 3p⁵