Applet: Half-lives

You can select an isotope in three different ways (see below). For each isotope you select:

the isotope's position on the chart is marked by the square green dot where the faint grey cross-hairs intersect;
certain data pertaining to the isotope is shown on the top left of the chart (i.e. the proton number Z, neutron number N, mass number A, half-life if any and type of the isotope.

Z - N chart (proton number versus neutron number)

Click on a white/yellow/blue/red dot to select any isotope

Click on a round yellow button to select one of the 10 elements listed

Colour-code:
stable nuclei	white
unstable nuclei, half-lives > 1000 years	yellow
unstable nuclei, half-lives < 1000 years	red
unstable nuclei, half-lives < 1 μs (micro-second)	blue

Click on a grey button to add/remove a proton/neutron

The numbers are taken from the compilation of G. Audi and A.H. Wapstra, Nucl. Phys. A595, 409(1995).