Question

How many electrons can be added to the fifth energy level?

Answer 1

`"50 e"^(-)`

Explanation:

The maximum number of electrons that can occupy a given energy level `n` is given by

`color(blue)(ul(color(black)("max. no. of e"^(-) = 2n^2)))`

The idea here is that the number of orbitals that are present in an energy level `n` is given by

`color(blue)(ul(color(black)("no. of orbitrals" = n^2)))`

As you know, a given orbital can hold a maximum of `2` electrons, which is why the maximum number of electrons that can be added to a given energy level `n` is twice the number of orbitals present on said energy level.

In your case, `n=5`, which refers to the fifth energy level, holds

`"no. of orbitals" = 5^2`

`"no. of orbitals" = 25`

This means that the maximum number of electrons that can be added to the fifth energy level is

`color(darkgreen)(ul(color(black)("max no. of e"^(-) = 2 * 25 = "50 e"^(-))))`