Key terms & definitions

The value approximately three-quarters of the way through ordered data, with about 75% of values below it.

The value approximately three-quarters of the way through an ordered distribution, with about 75% of the data below it.

An attempt to resist or overthrow an established ruler or government, often using force.

Training that develops a worker’s skills so they can carry out more advanced or different tasks.

Towards a river’s source, opposite to the direction in which its water flows.

The resultant upward force exerted by a fluid on an immersed object because pressure is greater on its lower surfaces than on its upper surfaces.

The upward force exerted by a fluid, such as water or air, on an object.

The overall upward force exerted by a fluid on an object because pressure is greater on its lower surfaces than on its upper surfaces.

The campaign that sent millions of urban young people to rural areas for work and political re-education, also breaking up Red Guard networks.

The movement of colder, deeper ocean water towards the surface.

A particular form of uranium whose nucleus contains 92 protons and 143 neutrons, giving a mass number of 235.

Relating to towns and cities, often densely populated.

A continuously built-up urban area that can include a central city and adjoining settlements.

A built-up area, such as a town or city, with a concentration of people, buildings and services.

Changes over time in a town or city’s population, economy, buildings, infrastructure and environment.

The densely populated, built-up central part of an urban area, where many jobs, services and transport connections are concentrated.

A lack of the resources, services or living conditions needed for an acceptable standard of life. It includes disadvantages in housing, education, health and employment, not just low income.

The development of towns, including their buildings, commerce and organisation.

The buildings, streets, housing, shops and other physical features of towns and cities.

Growing food within towns and cities, for example in community gardens or on unused land.

The activities carried out in a place, such as retailing, manufacturing or housing.

The activities or purposes of a place, such as housing, government, retail or finance.

A space in a town or city used to grow food, such as a domestic garden, school garden or shared community plot.

Increasing or improving vegetation and green spaces within a built-up area, for example through tree planting and creating parks.

An increase in the population living in a town or city, often accompanied by expansion of its built-up area.

An urban area that is warmer than its surrounding countryside.

The tendency for built-up urban areas to be warmer than the surrounding countryside.

An increase in the proportion of a population living in towns and cities.

The process in which an increasing percentage of a population lives in towns and cities.

Organising the development of a town or city, including its housing, infrastructure and services.