1. The problem statement, all variables and given/known data An electron with KE 5eV is incident on a H atom in its ground state. The collision A)must be elastic b)may be partially elastic c)must be completely inelastic d)may be completely inelastic More than one option may be correct 2. Relevant equations 3. The attempt at a solution In ground state energy of H atom is -13.6eV. Now the question remains if an electron collides does its KE remains conserved?