Free neutrons (unlike those in the nucleus of an atom) decay spontaneously into a proton, an electron and an antineutrino. The masses of these particles are (approx.)mn = 1.67492 × 10^-27 kg mp = 1.67262 × 10^-27 kg me = 9.10939 × 10^-31 kg The mass of the neutrino is zero (or nearly so). How much energy is released in this decay?