Write the symbol of the element from which this ion is derived and Write the formula of the oxide this ion forms.

Question

The partial (valence-level) orbital diagram for a 3+ ion is:

(3+ ion)

4s 3d 

Answer 1

The symbol for the element would be Cr (Chromium). I arrived at this from looking in period 4 and going over to the 4 d level. As the 3+ ion, of course, it would be Cr³⁺

The oxide formula would thus have to be Cr₂O₃