Neutron

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).

Related concepts

• activity
• atom
• decay constant
• electromagnetic radiation
• electron
• half-life
• molecule
• neutrino
• nuclear decay
• positron
• proton
• X-radiation