Which of the following is an endothermic process

Options

A. `Cs^(+)(g)+e^(-)rarrCs(g)`
B. `O^(-)(g)+e^(-)rarrO^(2-)(g)`
C. `C(g)+e^(-)rarrC^(-)(g)`
D. A and C both

Answer

B

Explanation

(A) `Cs^(+)(g)+e^(-) rarr Cs (g)` (exothermic process)
(B) Successive electron gain enthalpy is endothermic process.
(C ) First electron gain enthalpy of carbon is exothermic process