1. The problem statement, all variables and given/known data 1. What happens to a mercury atom that has been raised to its first exictation level by a collision with an electron? 2. If an electron with 30.0eV of energy were to his this atom, what energy would the electron have after it reflected off, and what energy level would the atom be in afterwards? [ANS: 2.66eV , n=2 energy level ] n4= 2.278 eV n3= 4.050 eV n2 = 9.113eV n1= 36.450 eV 2. Relevant equations 3. The attempt at a solution 1. The first exictation level is n=2, i dont really know whats its asking and there is no answer there. 2. I know how to get it, its 30 subtract the transitional energy between n=1 and n=2 , but i have a small question when an electron collides is the reflected energy always the subtracted energy between two energy levels?