7. What is the maximum number of d orbitals in a principal energy level?

2

5

3

1

5

Explanation:

The maximum numbers of d orbitals are 5. These are named as dz², dxy, dyz, dzx, dx² - y².

The number of maximum electrons accommodate in d orbitals are,

l = 2

2 (2 (2) + 1)

2 (4 + 1)

10

so maximum electrons in d subshell are 10.

The 1st and second energy level do not have d orbitals. Third energy level in addition to s and p orbitals contain d orbitals.

Energy level sublevel N of orbitals No of electrons

1 s 1 2

2 s 1 2

p 3 6 (total=8)

3 s 1 2

p 3 6

d 5 10 (total=18)