Three Types of Emissions & Half Life

Half-Life

The average time taken for the number of radioactive nuclei to halve.

Becquerels (Bq)

The unit of measurement for the activity of a radioactive substance.

Predictable half-lives

The behavior of large groups of radioactive nuclei which is predictable despite individual atom decay being random.

Constant half-life

The average time taken for the number of nuclei to halve remains constant for any one isotope.

Unstable isotopes

Isotopes that can have half-lives ranging from seconds to millions of years.

Alpha radiation

Radiation consisting of particles with two protons and two neutrons, strongly ionising and with a relative mass of 4.

Ionising emissions

Radiations that can remove electrons from atoms, causing ionisation; includes alpha, beta, and gamma radiation.

Beta radiation

High-energy electrons that are more ionising than gamma radiation but less than alpha radiation.

Aluminium foil

The material that stops beta radiation while allowing it to pass through common paper.

Gamma radiation

A weakly ionising radiation that causes less damage than alpha or beta but is stopped only by centimetres of lead or concrete.

Strongly ionising

A property of alpha radiation indicating it causes significant damage to matter.

Random decay

The unpredictable nature of decay in an individual radioactive atom.

Decay of radioactive nuclei

The process of the number of radioactive nuclei decreasing over time, predictable when viewed in large groups.

Paper

A material that can stop alpha particles despite their strong ionising capability.

Lead or concrete

Materials required to stop gamma radiation.

High-energy electrons

The particles that compose beta radiation.