The 3 types of radioactive decay, previously discussed are shown on the right.

A new law that is evident by studying radioactive decay is that the total number of nucleons cannot change.

This law is called the law of conservation of nucleon number.

The total number of nucleons (A) remains constant in any process.

One type, however, can change into the other type (protons into neutrons or vice versa).

The law holds for all types of ratiation.