A neutron is an electrically neutral hadron that, while stable inside the atomic nucleus, has an average lifespan of 12 minutes outside the atomic nucleus. Its stationary mass is 1.6492 X 10 ^ - 26 kg , which is slightly more than the proton (1.62614 X 10 ^ - 26 kg) and 1839 times the mass of an electron. Rutherford was the first scientist to predict the presence of a charge-neutral particle in the nucleus of an atom. The scientist James Chadwick (1891-1984) first discovered the existence of charge neutral neutrons in the nucleus of an atom in 1932 and proved that neutrons exist in all atomic nuclei except ordinary hydrogen (hydrogen-1). Atomic mass The mass of a unit is about 1 ⋅ 0075 atomic Mass Single. The neutron is located in the nucleus of the atom. Neutrons reduce their reciprocal repulsion so that atoms do not become unstable due to the reciprocal repulsion of positively charged protons in the nucleus. Under certain conditions, charge neutral neutrons break down to produce a proton , an electron and an antinutrino. This is thought to be the origin of the cathode ray or electron flow produced by the splitting of the radioactive element.