1. The problem statement, all variables and given/known data Calculate the uncertainty product ΔrΔp for the 1s electron of a hydrogen-like atom with atomic number Z. (Hint: Use <p> = 0 by symmetry and deduce <p^2> from the average kinetic energy) 2. Relevant equations All I have is the wavefunction. For a 1s, it takes the form: wavefunction = (Z/a0)^(3/2)*2exp(-Zr/a0) Where Z is the atomic number, a0 is the Bohr radius Other equations that I think I need include: The energy for a hydrogen-like atom: E = (-13.6 eV)(Z^2/n^2) Δr = √(<r^2> - <r>^2) Δp = √(<p^2> - <p>^2) <f> = ∫f(r)*P(r)dr That integral is from 0 to ∞, and the <> are supposed to denote averages. 3. The attempt at a solution I can find Δr no problem. Just use the above formula, where f(r) is r^2 for <r^2> and f(r) is r for <r>^2. The problem is finding the uncertainty in momentum. The above formula for momentum uncertainty should reduce down to Δp = √(<p^2>) And that's where I'm stuck; the hint isn't helping me much. For another problem, I found the uncertainty in KE by finding the uncertainty in <U> for a hydrogen atom, and then used <KE> + <U> = <E>, where <E> = -13.6/n^2. I'm not sure what the potential for a hydrogen-like atom is. Also, how can I get KE into momentum? I'm just confused on this part as a whole. Any help is appreciated! Thank you!