[Boxxxed]

So I've completed Chem I & II and I need to carry over some knowledge to my mineralogy class. Please refresh my memory.

Crystal field transitions occur between partially filled 3d orbitals. Ti, V, Cr, Mn, Fe, Co, Ni impurities will cause varying colours when substituted into the original mineral chemical composition. ie Fe replaces Mg.

So my question is, some of these elements have 4s orbitals, wouldn't the 3 orbitals be full then? Why would they be partially filled when there are electrons in the 4s orbital? It doesn't say whether or not it's in ground state. Clarification is appreciated.

[arit]

It all comes down to the order in which the atomic orbitals fill with electrons.
4s is actually filled before 3d, according to the aufbau principle. You can find
a more lengthy explanation at http://en.wikipedia.org/wiki/Aufbau_principle

[Boxxxed]

ah I remember that, thanks