Chapter 5: Nuclear physics — Part 5

01 What decay does to the nucleus

Radioactive decay is a change in an unstable nucleus. It can emit α, β and/or γ. The changes are spontaneous and random.

During α-decay or β-decay the nucleus changes to that of a different element.

Isotopes may be radioactive because of an excess of neutrons and/or because the nucleus is too heavy.

Emission increases stability and can reduce the number of excess neutrons. In β-emission:

neutron → proton + electron

02 Decay equations

α-decay

A decreases by 4, Z decreases by 2. A helium nucleus leaves.

β-decay

A unchanged, Z increases by 1 (a neutron becomes a proton; an electron is emitted).

γ-emission

A and Z unchanged. The nucleus loses energy as an EM wave.

Balance nucleon number and proton number on both sides of the nuclide equation.