Question

Transition metals can exhibit variable valency. It is because of:

• A. The smaller atomic radius
• B. The high screening effect
• C. The very less energy difference between (n-1) d subshell and ns subshell
• D. The high nuclear charge

Answer 1

The correct option is C The very less energy difference between (n-1) d subshell and ns subshell

The energy difference between (n-1)d and ns subshell is very less. Transition metals have (n-1)d and ns electrons.

After losing some s and d electrons, transition metals can acquire immediate half-filled and fully filled stable configurations.

They may have more than one such oxidation states.

Since both (n-1) d and ns take part in chemical bond formation.

Option C is correct.