In the chemical process called electron transfer, an electron is transferred from one atom or molecule to another. A simple electron transfer reaction is
A(g) + A(g) → A+(g) + A-(g)
In terms of the ionization energy and electron affinity of atom A, what is the energy change for this reaction? For a representative nonmetal such as chlorine, is this process exothermic? For a representative metal such as sodium, is this process exothermic?