Question

When electrons are added in the 6s orbital, what happens to the energy level of the 5d
orbitals? As a result after the electron enters 5d orbitals in the lanthanum, in which orbital
does the next electron enter in cerium?

Answer 1

Cerium has an electronic configuration of (outer shell) 4f1 5d1 6s2. So the next electron enters 6s orbital

Answer 2

To answer ur first question

The orbit in which the electrons will be added depends upon its energy level

And it is calculated by n + l

n is principal quantum no

L is azimuthal quantum no

So lower the n +l value of an orbital...electro s will be filled in tht orbit first

L for s orbital is 0

L for p orbital is 1

L for d orbital is 2

So 6s = 6+0 =6

5d = 5 +2 =7

Thus 6s fills first...

Regards.