|Graph of nuclear half-lives|
This map of nuclei shows the extraordinary range of half-lives that exists in nature. Along the central line drawn in black, we find the nuclei that are either stable or have a half-live longer than a billion years. Those nuclei which survive for a fraction of a second, however, (coloured in red) can be found on the borders of the diagram. A group of very heavy, very unstable nuclei can also be found around the 130 neutron, 85 proton mark. Among even heavier nuclei, we find an island of comparative stability (in mauve), where a group of isotopes have a half-life between the one- and the billion-year mark. The two heaviest natural nuclei, thorium 232 and uranium 238, are the solitary black dots in the mauve island.