1. The problem statement, all variables and given/known data A photon of wavelength 29 pm is scattered by a stationary electron. What is the maximum possible energy loss of the photon? (mass of electron = 9.11 × 10-31 kg, h = 6.626 × 10^-34 J · s, c = 3.00 × 10^8 m/s) 3. The attempt at a solution After an hour or so, I'm not getting the right answer. 29pm = 29x10-11m Ei = Ef + KE Ei - Ef = ΔE = h(c/Δλ) I set Θ = 180 and worked out λf = (h/mec)(1-cosΘ) + λi = 4.854212x10-12m ΔE = 6.626x10-34 (3x108/4.854212x10-12) = 4.095x10-14 j to convert to eV, i divided the above by 1.6 x10-16 but it doesn't give me the correct answer.