# What values of #l#, #m_l#, and #m_s# are possible for #n = 3#?

##### 2 Answers

Well, your set of quantum numbers is not "allowed" for a particular electron because of the value you have for **angular momentum quantum number**.

The values the angular momentum quantum number is allowed to take go from zero to **principal quantum number**.

So, in your case, if **3**, the values **0**, **1**, and **2**. Since **3**, this puts it outside the allowed range.

The value for

Likewise, **spin quantum number**, has an acceptable value, since it can only be

Therefore, the only value in your set that is not allowed for a quantum number is

There are 4 quantum numbers which describe an electron in an atom.

These are:

If

In your question

If

If

If

These are all the allowed values for

Note that in an atom, no electron can have all 4 quantum numbers the same. This is how atoms are built up and is known as The Pauli Exclusion Principle.