1. The problem statement, all variables and given/known data (a) What is the minimum energy (in electron volts) that is required to remove the electron from the ground state of an ionized atom (Z=2)? (b) What is the ionization energy for this ion? 2. Relevant equations After doing what I got the answer for part (b)... but I don't know what part (a) requires. I thought this number would be 13.6 eV, but it's not. What exactly is part (a) asking? 3. The attempt at a solution I used the equation E= -13.6*(Z^2/n^2). I plugged in 2 for Z and 1 for n.