- 84 - Hydrogen Reaction Equations 1. Molecular dissociation H2 H + H.--The equilibrium relation between molecular and atomic hydrogen involved in molecular dissociation at absolute temperature T is (39) NH N 2H2 mm3k T 3 UH UH EH 2/kT H - H 1 ___ T3/2 ~ e 2(5.1) NH2 mH h2 UH2 where mH = atomic weight of H mH = atomic weight of H2 2 uH = partition function of H UH2 = partition function of H2 E' = dissociation energy of H2 H2 k = Boltzmann's constant h = Planck's constant The partition function of atomic hydrogen is uH = g. j Xj/kT (5.2) J where gj = statistical weight of j-th term Xj = excitation energy of j-th term