Which of the following require maximum amount of energy ?

Options

A. `Ca(g) rarr Ca^(+) (g)`
B. `Ca^(+) (g) rarr Ca^(2+)(g)`
C. `Mg^(+)(g)rarrMg^(2+)(g)`
D. `Mg^(2+)(g) rarr Mg^(3+)(g)`

Answer

D