Question

The metal that shows highest and maximum number of oxidation state is:

• A. Fe
• B. Mn
• C. Ti
• D. Co

Answer 1

The Correct Option is B

Manganese (Mn) has the highest oxidation state (+7, as in MnO₄^-) in the 3d series metals. It also exhibits multiple other oxidation states.

Answer 2

Step 1: Recall the trend of oxidation states across transition metals
Transition elements exhibit multiple oxidation states because both (n–1)d and ns electrons can participate in bonding. The number of oxidation states usually increases toward the middle of the transition series and then decreases again toward the end.

Step 2: Consider the 3d series elements (Sc to Zn)
Here are their maximum oxidation states:
Sc (+3), Ti (+4), V (+5), Cr (+6), Mn (+7), Fe (+6), Co (+3), Ni (+2), Cu (+2), Zn (+2).

We see that the number of possible oxidation states increases up to manganese (Mn) and then decreases again.

Step 3: Explain why Mn shows the maximum variety
Manganese has the ground-state configuration [Ar] 3d⁵4s². Because it has 7 valence electrons, it can lose these in various combinations to give a wide range of oxidation states from +2 to +7. This allows Mn to form compounds such as:

• Mn²⁺ in MnCl₂
• Mn³⁺ in Mn₂O₃
• Mn⁴⁺ in MnO₂
• Mn⁶⁺ in MnO₃
• Mn⁷⁺ in KMnO₄

Hence, manganese displays the largest number of oxidation states among all elements in the periodic table.

Step 4: Key point on stability of oxidation states
In Mn, oxidation states +2, +4, and +7 are particularly common, showing its versatility in both redox and coordination chemistry. This behavior is due to the half-filled 3d⁵ stability and the similar energies of the 3d and 4s orbitals, which enable easy electron removal or sharing.

Final answer

Mn