In which of the following oxometal anions does the transition metal exhibit an oxidation state equal

Question

In which of the following oxometal anions does the transition metal exhibit an oxidation state equal to its group number?

Professor PC Thomas Classes · Answer

In $	ext{CrO}_4^{2-}$, Chromium is in the +6 oxidation state. Chromium belongs to Group 6 of the periodic table, so its oxidation state equals its group number.