Neutrons Changed Everything

Key properties of neutrons are summarized below:

• Mean square radius of a neutron is ~ 0.8 x 10^-15m (0.8 fermi)

• The mass of the neutron is 939.565 MeV/c²

• Neutrons are ½ spin particles – fermionic statistics

• Neutrons are neutral particles – no net electric charge.

• Neutrons have non-zero magnetic moment.

• Free neutrons (outside a nucleus) are unstable and decay via beta decay. The decay of the neutron involves the weak interaction and is associated with a quark transformation (a down quark is converted to an up quark).

• Mean lifetime of a free neutron is 882 seconds (i.e. half-life is 611 seconds ).

Without neutrons, harnessing nuclear energy would be impossible.