Which of the following in an energy consuming process ?

Options

A. `O(g) +e^(-) to O^(-) (g) `
B. `Na^(+) (g) + e^(-) to Na(g) `
C. `O^(-) (g) +e^(-) to O^(2-) (g) `
D. `O^(2-) (g) to O^(-) (g) +e^(-)`

Answer

C

Explanation

it refers to second electron affinity which is -ve.