Radioactivity

Definition

Radioactivity is the process by which unstable atomic nuclei lose energy by emitting radiation. This can include alpha particles, beta particles, and gamma rays.

5 Must Know Facts For Your Next Test

1. Radioactive decay occurs spontaneously and results in the transmutation of elements.
2. The three main types of radioactive decay are alpha decay, beta decay, and gamma decay.
3. Alpha particles consist of two protons and two neutrons; they have a +2 charge and are relatively heavy.
4. Beta decay involves the emission of an electron or positron; beta particles are lighter than alpha particles but more penetrating.
5. Gamma rays are high-energy photons with no mass or charge, making them highly penetrating and dangerous.

Review Questions

Related terms

Half-life:

The time required for half the atoms in a sample of a radioactive substance to undergo decay.

Nuclear fission:

A nuclear reaction in which a heavy nucleus splits into smaller nuclei with the simultaneous release of energy.

Isotope:

Variants of a particular chemical element which differ in neutron number while retaining the same number of protons.