Chapter 13, Problem 138CP

Think of forming an ionic compound as three steps (thisis a simplification, as with all models): (1) removing anelectron from the metal, (2) adding an electron to thenonmetal, and (3) allowing the metal cation and nonmetalanion to come together.
a. What is the sign of the energy change for each ofthese three processes?
b. In general, what is the sign of the sum of the first twoprocesses? Use examples to support your answer.
c. What must be the sign of the sum of the threeprocesses?
d. Given your answer to part c, why do ionic bondsoccur?
e. Given your explanations to part d, why is NaCl stablebut not ${\text{Na}}_{\text{2}}{\text{Cl}}_{\text{2}}{\text{and NaCl}}_{\text{2}}$ ? What about MgOcompared to ${\text{MgO}}_{\text{2}}{\text{and Mg}}_{\text{2}}\text{O}$ ?