Which of the following transitions involves maximum amount of energy?

Options

A. `M^(2+)(g) to M^(3+)(g)`
B. `M^(+)(g) to M^(2+)(g)`
C. `M(g) to M^(+)(g)`
D. `M^(-)(g) to M(g)`

Answer

A

Explanation

Greater the effective nuclear charge, more tightly the electrons will be held by the nucleus and hence larger energy will be required to remove further electron. Hence among given options , `M^(2+) to M^(3+)` transition will require maximum energy.