The specific heats, CP and CV of a gas of diatomic milecules, A, are given (in units of J mol–1 K–1) by 29 and 22, respectively. Another gas of diatomic moleucles, B, has the corresponding values 30 and 21. If they are treated as ideal gases, then :
(1) Both A and B have a vibrational mode each
(2) A is rigid but B has a vibrational mode.
(3) A has a vibrational mode but B has none.
(4) A has one vibrational mode and B has two.
