Chapter 7, Problem 7.143QP

When two atoms collide, some of their kinetic energy may be converted into electronic energy in one or both atoms. If the average kinetic energy is about equal to the energy for some allowed electronic transition, an appreciable number of atoms can absorb enough energy through an inelastic collision to be raised to an excited electronic state. (a) Calculate the average kinetic energy per atom in a gas sample at 298 K. (b) Calculate the energy difference between the n = 1 and n = 2 levels in hydrogen. (c) At what temperature is it possible to excite a hydrogen atom from the n = 1 level to n = 2 level by collision? [The average kinetic energy of 1 mole of an ideal gas is $(\frac{3}{2})RT$.]