Question

Question #01331

Answer 1

3s

Explanation:

You can see the relation between Energy of the orbitals and principal quantum number as below
`E= -(13.6/n^2)eV`

So, 2s orbital has `E= -(13.6/2^2)eV = -3.4 eV`
and
3s orbital has `E= -(13.6/3^2)eV = -1.51 eV`

So, 2s has lower energy and it is stable,
and 3s has higher energy.