Key terms & definitions

A magnetic field with the same strength and direction throughout a region.

Motion at a constant speed in a straight line, so equal distances are travelled in equal time intervals.

Motion at constant speed.

Motion at a constant speed in an unchanging direction.

Motion at a constant speed in a constant direction.

Action taken by one country without acting jointly with other countries.

A country giving up its weapons without requiring other countries to do the same first.

The reduction or removal of a country's weapons without requiring other countries to do the same.

The removal of a country’s own nuclear weapons without making this conditional on other countries doing the same.

Not registered as a company with a separate legal identity from its owners.

An effect that was not intended when a technology or process was introduced.

A harmful effect that was not intended when a product or process was introduced.

The United States as a single nation, which Lincoln sought to preserve against southern secession.

The set of elements that belong to $A$, to $B$, or to both sets.

The members belonging to either set or both. $A\cup B$ means ‘A or B, including both’.

Support for keeping the United Kingdom together. In Northern Ireland, unionists support Northern Ireland remaining part of the UK.

A person who supported keeping Ireland united with Great Britain and opposed Irish Home Rule.

In Northern Ireland, a person who supports Northern Ireland remaining part of the United Kingdom.

People who want Northern Ireland to remain part of the United Kingdom.

A far-right political organisation founded by Oswald Mosley in 1948 which promoted anti-immigration policies.

A mood disorder involving depressive episodes without manic or hypomanic episodes. Depressive episodes can recur, with recovery between them.

Every whole number greater than 1 can be expressed as a product of primes in exactly one way, apart from the order of the factors.

A result that distinguishes one possible ion from all the other ions being considered.

A distinctive feature or benefit that gives customers a particular reason to choose a product or service over competing alternatives.

A quality presented as distinguishing a product from its competitors.

The key benefit of a good or service that distinguishes it from competitors and can be emphasised in advertising and promotion.

An agreed standard used to express the magnitude of a quantity, such as grams for mass or cubic centimetres for volume.

A standard used to express a measurement, such as the second for time or the metre for length.

A standard amount used to express a measurement, such as a metre for length or a second for time.

The agreed quantity used to state a measurement, such as a metre or a second.