Question

How many electron in a given atom can have the following quantum numbers? $n=3,l=2,m=+2,s=+1/2$

• A. $1$
• B. $18$
• C. $14$
• D. $7$

Answer 1

The correct option is A $1$

Only one electron in a given atom can have the set of quantum numbers given in the question.

Explanation:

No two electrons in an atom can have the same set of quantum numbers.

The first quantum number is the principle quantum number , which is

n=3

This means the electron is in the third energy level (shell).

The second quantum number, the angular momentum , is

l=2

and means the electron is in the

d sublevel (subshell).

The third quantum number, the magnetic quantum number ,

$m_l$=2

represents one of the five

3d orbitals.

Lastly, we have the spin quantum number ,

$m_s=+1/2$

It indicates the direction of the spin of the electron.