# How many electrons can have the quantum number set n=5 and ml=1?

##### 1 Answer

#### Explanation:

As you know, each electron has a **unique set** of quantum numbers that describes its exact location in an atom.

In your case, you are given two qunatum numbers, *principal quantum number*, and

The principal quantum number describes the **energy level**, or energy *shell*, on which the electron resides. Now, notice that the values the magnetic quantum number can take *depend* on the value of *angular momentum quantum number*.

For an electron that has

#l = {0; 1; 2; 3; 4}#

As you can see, the magnetic quantum number can take values from

#l = { 1; 2; 3; 4}#

FInally, the *spin quantum number*,

#m_s = {-1/2; +1/2}#

This means that you will have

#n = 5; l=1; m_l = 1: m_s = +- 1/2# #n = 5; l=2; m_l = 1: m_s = +- 1/2# #n = 5; l=3; m_l = 1: m_s = +- 1/2# #n = 5; l=4; m_l = 1: m_s = +- 1/2#

SImply put, two electrons of opposite spins can share **one orbital** (given by *subshell* (given by

Therefore, total of