... binds the proton and the neutron together. So the deuteron will weigh 2. 0159 – 0.0 024 = 2. 0135 amu.Decay RatesOn SAT II Physics, you probably won’t be expected to calculate how long it takes ... Elementary ParticlesOn the SAT II, you will not need to apply your knowledge of any elementary particles aside from the proton, the neutron, and the electron. However, the names of some other particles ... the mass of a neutron is 1.00 86 amu. Curiously, though, the mass of an alpha particle, which consists of two protons and two neutrons, is not 2( 1.0073) + 2( 1.00 86) = 4.0318 amu, as one might...