Question

why 4s orbital is lower in energy than 3d orbital?​

Answer 1

The simple answer is because 4s orbital is lower in energy than 3d orbital when they are empty. ... So this explains why even though we fill the 4s before 3d orbitals, we will still ionize 4s electrons before 3d electrons.The simple answer is because 4s orbital is lower in energy than 3d orbital when they are empty. ... So this explains why even though we fill the 4s before 3d orbitals, we will still ionize 4s electrons before 3d electrons.

Answer 2

Explanation:

as we all know

S =0

P = 1

D = 2

F = 3

for 4s

4+0 = 4

and for 3d

3+2 = 5

so 4s orbital has lower energy than 3d orbital