Key terms & definitions

Prejudice or discrimination based on race, including the belief that racial groups have fixed characteristics or can be ranked as superior and inferior.

Prejudice or discrimination based on race, skin colour or ethnic background, often involving the belief that one racial group is superior to another.

Beliefs that racial groups are superior or inferior, and attitudes or practices that disadvantage people on racial grounds.

A mechanism consisting of a straight toothed rack and a circular gear called a pinion, which converts between rotary and linear movement.

A change of focus within a shot that redirects attention between subjects at different distances from the camera.

The sideways distortion of a frame, such as a rectangle changing into a parallelogram.

The National Labour Service, which organised labour on public projects. From 1935, six months’ service was compulsory for young men aged 18–25.

Radio Detection and Ranging: technology that uses radio waves to detect objects such as approaching aircraft.

The use of reflected electromagnetic waves to detect an object and determine information such as its position.

A circular graph with axes radiating from a central point, used to display values for different categories or variables.

Energy travelling as electromagnetic waves. Incoming sunlight is mainly short-wave radiation; Earth emits energy as long-wave infrared radiation.

The transfer of energy by electromagnetic waves.

Energy transferred by waves or particles emitted from a source.

The transfer of energy by electromagnetic waves.

The transfer of energy by electromagnetic waves. A hot grill emits infrared radiation that food absorbs.

A balance in which radiation is absorbed and emitted at the same rate, so there is no temperature change due to radiation.

A measure of the risk of harm from exposure of the body to radiation.

A measure of the risk of harm resulting from exposure of the body to radiation. It is measured in sieverts (Sv), often expressed as millisieverts (mSv).

The use of radiation to treat cancer, rather than to produce a diagnostic image.

A state in which radiation is absorbed and emitted at equal rates, so radiation causes no overall change in temperature.

A feminist approach which sees patriarchy as the fundamental source of women’s oppression and argues that legal reform alone cannot remove deeply rooted male power.

The process through which someone comes to adopt extremist beliefs, which may include supporting or carrying out violence.

A campaign for fundamental political change, such as widening voting rights and challenging unequal parliamentary representation.

Members of the Republican Party who wanted stronger federal action to reconstruct the South and secure equal civil and political rights for African Americans.

The number or expression beneath a root sign; in $5\sqrt7$, the radicand is $7$.

The repeated word or phrase at prescribed line endings in a traditional ghazal.

Describes an unstable nucleus that spontaneously emits radiation as it decays.

The unwanted presence of radioactive material on or inside an object or organism, or in the environment.

The unwanted presence of materials containing radioactive atoms on other materials.

The breakdown of unstable atomic nuclei, releasing energy that contributes to Earth's internal heat.