Same Element - Two great flavours!
Helium has two isotopes (stable forms), helium-4 (2 protons, 2 electrons and 2 neutrons) and helium-3 (2 protons, 2 electrons and 1 neutron). The '3' or '4' relates to the total number of protons and neutrons found in the nucleus of the atom. At room temperature, both isotopes are chemically identical and difficult to distinguish from one another.
The first significant difference to consider is the relative abundance of the two isotopes. Helium-4 constitutes almost 99.99% of all the helium found on Earth, helium-3 is incredibly rare. It is only in the last 40 years that siginificant quantities of helium-3 have become available to allow experiments to be performed.Prev Next