1. Under the action of suitable radiation a diatomic molecule splits into two atoms. The ratio of the number or dissociated molecules the total number or molecules is a . Temperature where the vibrational modes of the diatomic molecule are excited. 2. Find the total translational kinetic energy and the rms speed of the molecules of 10 liters of helium gas at an equilibrium pressure of 3. (a) Find the specific heat capacity at constant volume for a gas of H2 molecules and H20 molecules. (b) How do the specific heat capacities change if the gas is liquefied or solidified?