Answer
See explanation.
Work Step by Step
a. The ideal monatomic gas will increase more in temperature. Its molar heat capacity is less than that of the ideal diatomic gas.
b. Physically, when energy is added to a mole of the diatomic gas, the molecules have rotational degrees of freedom. Some of the input energy goes into their spinning modes, leaving less available to increase the translational kinetic energy of the molecules.
The result is a lower final temperature than that of a mole of ideal monatomic gas to which the same amount of energy has been added.
