# What is the electron configuration for helium?

Jun 26, 2016

$\text{He: } 1 {s}^{2}$

#### Explanation:

Helium, $\text{He}$, has an atomic number equal to $2$, which means that it has $2$ protons in its nucleus.

A neutral helium atom will thus have $2$ electrons surrounding its nucleus. This means that the electron configuration for helium has to account for only $2$ electrons.

Both of these electrons are located on the first energy level, in the only subshell, and consequently only orbital available to them.

More specifically, both electrons will occupy the $1 s$ orbital, the only orbital located in the $s$ subshell.

The electron configuration will thus be

$\textcolor{g r e e n}{| \overline{\underline{\textcolor{w h i t e}{\frac{a}{a}} \textcolor{b l a c k}{\text{He: } 1 {s}^{2}} \textcolor{w h i t e}{\frac{a}{a}} |}}}$

Here's how the electron configuration of helium looks compared with that of hydrogen, $\text{H}$, which only has $1$ electron surrounding its nucleus.