Radioactive Decay

This applet simulates the decay of atomic nuclei.
You can specify the half-life of the nuclei.

If the applet does not appear, please try the following:
(1) Download the Java software from
(2) Go to the menu: Tools > Turn off Pop-Up Blocker.
(3) Tools > Internet Options > Advanced > Security > Allow Active Contents.
(4) Start Menu > All Programs > Java > Configure Java > Security and then add this website to the Exception Site List.

After the time indicated by the half-life, half of the number of atomic nuclei would have decayed.

Right-click here to download this page and the Java Class File.