1E.7

[805594676]

For part b, why is this considered an excited state?

[Vivian Kim 3F]

Hey I think that its in the excited state cause that electron in the 2p orbital could be paired with the 2s orbital first.

[Grace Chen 3F]

I think if part (b) is in ground state, then the second orbital of 2p should have an upward spin (normally, electron first have upward spins and fill in the orbital, then downward spin e- will pair with upward spin e-). I think any electron configuration that does not look normal will be considered as excited state.

[Omar Alami 3H]

Hi,

Part B would be considered an excited state because the filling of the orbitals, specifically 2s, does not follow our normal rules. One of them being that that the lower energy levels should be filled up before the higher energy levels. 2p has a higher energy than 2s, so 2s should have 2 electrons(with opposite spin) filling up its orbital before the 2p gets filled. Since this rule isn't followed the electron configuration must of had an electron excited to a high energy level(2p), making it an example of an excited state.

[Qinyan Feng 1H]

Hi

I believe according to Hund's rule, we should fill all orbitals with electrons in the same direction first, and since the electron in the second orbital in 2p has an opposite direction as the other two, this arrangement is considered an excited state.

Hope that helps!

[Jelix Tsan 2H]

This is because in its ground state, the three electrons in the 2p subshell should all have parallel spins and be located in different orbitals. Only after the three orbitals are partially inhabited are electrons added that have opposite spins.