Nuclear radiation

Definition

Nuclear radiation is the emission of energy as electromagnetic waves or subatomic particles from the nucleus of an unstable atom. It includes alpha, beta, and gamma radiation.

5 Must Know Facts For Your Next Test

1. Alpha particles are helium nuclei and can be stopped by a sheet of paper.
2. Beta particles are high-energy electrons or positrons that can penetrate paper but are stopped by aluminum.
3. Gamma rays are high-energy photons with no mass that require dense materials like lead for shielding.
4. Radiation is measured in units such as becquerels (Bq) and sieverts (Sv).
5. The half-life of a radioactive substance is the time it takes for half of the radioactive atoms to decay.

Related terms

Alpha Decay:

A type of radioactive decay in which an atomic nucleus emits an alpha particle and transforms into a new element.

Beta Decay:

A type of radioactive decay in which a neutron transforms into a proton or vice versa, emitting a beta particle.

Half-Life: The time required for half the atoms in a sample of a radioactive isotope to decay.