Along with the proton, the neutron is one of the building blocks of the atomic nucleus.
The mass is 1.67493×10-27 kg.
The neutron is electrically neutral, hence its name. A free neutron is not stable,
but decays with a half-life of 10.2 minutes.
History
In 1920, the New Zealand physicist Ernest Rutherford, first baron of Nelson (1871 - 1937)
suggested that the nucleus consisted of positive protons and neutrally charged particles,
possibly being a proton and an electron bound in some way.
A year later, the American chemist William Draper Harkins (1873 - 1951) first named
the hypothetical particle a "neutron".
The existence of the neutron was first demonstrated in 1932 by the English physicist
James Chadwick (1891 - 1974).
