Question

When n = 2 for an electron, the magnetic quantum number can have ______ values.

• A. three
• B. two
• C. nine
• D. six

Answer 1

The correct option is A three

The possible values of angular momentum quantum number is given by $l$ = 0, 1, 2,..., (n-1)

For n = 2;
$l$ = 0, 1
The number of possible values of magnetic quantum number is given by (2$l$+ 1)
Substituting $l$= 1 we get,
Number of possible values of magnetic quantum number in second shell = (2 x 1 +1)
= 3
Therefore, magnetic quantum number can take three values for n = 2.