Calculate, by explicit summation, the vibrational partition function, and the vibrational contribution to the molar internal energy of I2 molecule at a) 100K b) 298K given that its vibrational energy levels lie at the following wavenumbers above the zero-point energy level: 0, 213.30, 425.39,636.27, 845.93 cm^-1. What proportion of I2 molecules are in the ground and the first two excited levels at the two temperatures. Calculate the vibrational contribution to the molar entropy of I2 at the two temperatures?