When a photon is emitted by a hydrogen atom, the photon carries a momentum with it. (a) Calculate the momentum carried by the photon when a hydrogen atom emits light of wavelength 656.3 nm. (b) With what speed does the atom recoil during this transition ? Take the mass of the hydrogen atom = 1.67 x 10-27 kg. (c) Find the kinetic energy of recoil of the atom.
