3. Bohr's Quantum Model of the Atom An electron initially in the n = 3 state of a one-electron atom of mass M at rest undergoes a transition to the n = 1 ground state. (a) (2 marks) Show that the recoil speed of the atom from emission of a photon is given by 8hR v = 9M (b) (2 marks) Calculate the percentage of the 3-1 transition energy that is carried off by the recoiling atom if the atom is deuterium