For which of the following reaction `deltaH^(o)` value is equal to the first ionization energy of Ca is?

Options

A. `Ca^+ (g) rarr Ca^(2+)(g) + e^-`
B. `Ca (g) rarr Ca^(+)(g) + e^-`
C. `Ca (s) rarr Ca^(+)(g) + e^-`
D. `Ca (g) rarr Ca^(2+)(g) + 2e^-`

Answer

B