1. The problem statement, all variables and given/known data The energy required to dislodge electron from sodium and metal via the photoelectric effect is 275 kJ/mol. What wavelength in nm of light has sufficient energy per photon to dislodge an electron from the surface of sodium? 2. Relevant equations How do I convert 272 kJ/mol to J so that it cancels out Plank's Constant and the light leaving me with m which I can convert to nm? 3. The attempt at a solution I kept trying and failing. The book has the answer as 435 nm and unfortunately, it doesn't show the work. I'd like to know how it got the 435 nm.