Electron Config. for Sg+2: Explained

[zaddyzad]

Homework Statement

For Sg+2 what is the electron configuration.

The Attempt at a Solution

My immediate response would be [Rn] 7s2, 5f14, 6d2
but the answer is [Rn] is 5f14 6d4

Can someone explain this to me?

 

[jfizzix]

If the answer is correct, this means the math works out that the 7s-shell valance orbitals are at an actually higher energy than the 6d or 5f orbitals. I think this might be the answer, but I'm not familiar enough with calculations to say for sure.

 

[Borek]

Per analogy with transition metals I would expect 7s electrons to be lost first. Why makes you think it should be 6d?

 

[zaddyzad]

I suppose I don't fully understand electron orbitals concept. Upon a little more brain digging, we remove heighest energy level electrons first?

 

[jfizzix]

Yes, the electrons in an atom in its ground state are arranged in the orbitals from lowest energy to highest. If the 7s orbitals happen to be at a higher energy than the 6d or 5f orbitals, then the 6d and 5f orbitals would fill up before the 6s orbital fills up.