The following quote about ammonia (NH3) is from a textbook of inorganic chemistry: "It is estimated that 26% of the hydrogen bonding in NH3 breaks down on melting, 7% on warming from the melting to the boiling point, and the final 67% on transfer to the gas phase at the boiling point." From the standpoint of the kinetic energy of the molecules, explain
(a) Why there is a decrease of hydrogen-bonding energy on melting and
(b) Why most of the loss in hydrogen bonding occurs in the transition from the liquid to the vapor state?