A metal 'M' belonging to the first transition series exhibits the maximum number of oxidation states. It forms three oxides, denoted as X, Y, and Z, where the metal 'M' is in +2 , +4 , and +7 oxidation states respectively. The acid-base nature of the oxides X, Y, and Z respectively is :

Step-by-step solution

The metal in the 3d transition series that exhibits the maximum number of oxidation states (from +2 to +7 ) is Manganese (Mn). The oxides formed are MnO (oxide X, +2 state), MnO ₂ (oxide Y, +4 state), and Mn ₂ O ₇ (oxide Z, +7 state). For a given transition metal, the acidic character of its oxides increases with an increase in the oxidation state. Lower oxidation state oxides are basic, intermediate ones are amphoteric, and the highest oxidation state oxides are acidic. Therefore, MnO is basic, MnO ₂ is amphoteric