Explain the energy transfers when ionic bond are made, include ionization energy and electron affinity.

In ionic bonds, the metal is donor of electrons (loses electrons) and become a positively charged ion (cation) and nonmetal is acceptor of electrons (accepts those electrons) and become a negatively charged ion (anion). 
Ionization energy of the metal (easy to remove valence electrons) is lower than nonmetal and  electron affinity of the nonmetal is higher than metal.