Question

In the transition series why is the configuration 3d 4s and not 4s 3d since 3d has higher energy?​

Answer 1

Answer:

Radius of nth shell is taken in this place.

Explanation:

Yes, You're right. 3d orbital has higher energy than that of 4s orbital. The energy of orbitals can be related by (n+l) rule. The orbital having greater (n+l) number will have greater energy.

For 4s orbital, n = 4, l = 0, (n+l) = 4

For 3d orbital, n = 3, l = 2, (n+l) = 5

Though 3d orbital have higher energy than 4s orbital, the distance of 4s orbital from the nucleus is greater than that of 3d orbital, i.e. N shell have greater radius than M shell. This is the reason for arrangement.

Thank You

Answer 2

Answer:

BECAUSE OF( n+l) RULE

Explanation: