Which metal in the first series of transition metals exhibits +1 oxidation state most frequently and why?

Name the oxometal anions of the first series of transition metals in which the metal exhibits the oxidation state equal to its group number.

A transition metal exhibits higher oxidation states in oxides and flourides. Why?

Name the oxometal anions of the first series of the transition metals in which the metal exhibits the oxidation state equal to its group number.

Which transition metal can show highest oxidation state ?

Most of transition metals show variable oxidation states. Explain