Which of the following reaction involves the liberation of energy?

Options

A. `Na_((s)) to Na_((g))^(+) `
B. `Cl_(2(g)) to 2Cl_((g))`
C. `Na_((g))^(+) +Cl_((g))^(-) to NaCl_((s))`
D. `NaCl_((s)) to Na_((g))^(+) +Cl_((g))^(-)`

Answer

C