Consider a BG cavity chamber with equilibrium-thickness copper walls. It is first filled with a mass m of air and then by the same mass of hydrogen. Assuming identical photon irradiations in the two cases, what is the charge ratio qair/qH? Assume that (W/e), = 36.5 J C- and that the mean electron energy E = 0.80 MeV. Note that for hydrogen (Sal/ P)o.8 Mey = 3.883 MeV cm2g-1. Answer: qair / 9H = 0.466