Complete the following nuclear equation p+ -----> n + ... + ...

This is a proton decaying into a neutron and two other subatomic particles. Here you have to consider various conservation laws, including: baryon number, lepton number and charge. (Energy and momentum are assumed to be conserved.)  Firstly, baryon number. This is conserved because the baryon number of on the left hand side is 1 (from the proton) and 1 on the right hand side from the neutron.  Secondly charge must be conserved, This is because on the left hand side there is a proton of charge +1 and on the right hand side there is a neutron of charge 0 so there must be another particle on the right hand side to balance the charge. This is a positron, the antiparticle of the electron (e⁺). Thirdly, lepton number. On the left hand side of the equation it is zero and on the right hand side of the equation it must therefore also be zero. However, we now have a positron on the right hand side meaning the lepton number on the right hand side is -1 (minus because it's an antiparticle). Therefore another particle with a lepton number of +1, charge 0 and baryon number 0 must be added so that all conservation laws are satisfied. This is a neutrino ν.  Therefore the equation is p⁺ ----> n + e⁺ + ν