1. The problem statement, all variables and given/known data 2. Relevant equations KE = 3/2 R/NA T 3. The attempt at a solution By using the formula above, I used 2.4 x 10^-14 J as the mean translational KE , but it should be 1.2x10^-14 , why? I thought the mixture contains both deuterium nucleus and the proton? Why half KE of mixture?