In radioactive beta decay, a
neutron turns into a
proton or a proton into a neutron,
with the atomic nucleus emitting an
electron plus antineutrino and a
positron plus
neutrino, respectively.
In this case, electron and positron are called beta particles
(denoted by the Greek letters β- and β+) to indicate that
they are formed inside the atomic nucleus.
History
The name was coined by the New Zealand physicist Ernest Rutherford (1871 - 1937) Baron of Nelson.
By 1900, the French physicist Antoine Henri Becquerel (1852 - 1908) had already shown
that the particles were electrons.
In 1914, the English physicist James Chadwick (1891 - 1974) demonstrated
the continuous energy distribution of these electrons.
