# Energy of the atomic orbitals!

1. Jan 6, 2012

### Chemist20

1. The problem statement, all variables and given/known data
Compare the energies of the 1s, 2s, 3s and 3p orbitals for both the HE and He+. For He assume that one electron is always in the 1s orbital. State any other assumptions you have made

2. The attempt at a solution
I think:
He can be either 1s1 2s1 or 1s2
He+ has to be 1s1.

For He 1s2, the 1s orbital has a lower energy than in the case of He+ and since there is a greater shielding, this allows the 2s, 3s and 3p to rise in energy. Hence these have a higher energy than in He+.

For He1s1 2s1 is basically the same thing, only that now 1s1 has a higher energy than 1s2 but still lower than He+ and 2s1 has a lower energy than in the other cases.

Thanks!!

2. Jan 7, 2012

### Simon Bridge

In He+, you have 2 protons attracting one electron.
Does this mean that the electron is more or less tightly bound to the nucleus?
Is "tightly bound" a lower or a higher energy?

If you are just using a shielding model, then isn't He going to be basically like hydrogen?

(Does your model include spin-orbit coupling?)