Answer:
6 electrons
Explanation:
To solve this question lets determine the possible quantum numbers for the principal quantum number n = 4.
For the quantum number l which describes the shape of the orbital, we have the possible values : 0 to n-1.
Thus, for n = 4 the l can assume the values 0, 1, 2, 3 ( 4 possible shapes )
For the angular quantum number, ml, which tell us the orientation in space,we have the values - l to + l.
So lets determine the number of orbials which can have the values -l for n=4
l = 0 ml = 0
l= 1 ml = -1,0,1
l= 2 ml = -2, -1, 0, 1, 2
l= 3 ml = -3,-2,-1,0,1,2,3
So we have three orbital with ml = - 1 and from Pauli´s exclusion principle we can have up two electrons in each orbital. Thus for n= 4 we can have up to 6 electrons with ml = -1
