Key terms & definitions

A conflict over which ruling family or claimant should hold the throne.

A marriage intended to strengthen a ruling family’s political position, alliances or claim to power.

A marriage that connects ruling families and helps secure their political power and succession.

A royal family whose members inherit the throne across successive generations.

A succession of rulers belonging to the same family.

A harmful consequence of a social institution or practice for individuals, groups or wider society.

A family in which relationships or behaviour harm members or prevent their needs being met, for example through abuse or neglect.

A learning difficulty that affects accurate and fluent reading and spelling; it does not mean a person lacks intelligence.

An imagined society characterised by injustice, suffering or oppressive control.

A series of 12 preferred resistor values in each factor-of-ten range, traditionally associated with $\pm10\%$ tolerance.

The eardrum is a thin membrane in the ear that vibrates when sound waves reach it.

A powerful noble who governed a large region called an earldom on behalf of the king.

A territory governed by an earl, a high-ranking noble with administrative and military responsibilities.

The highest-ranking nobles in Anglo-Saxon England, who governed large regions called earldoms.

The mixture of gases surrounding the Earth during the earliest part of its history.

The period from approximately 1500 to 1750, between the medieval period and the later industrial age.

An alert issued after a hazard has been detected but before its effects reach some people.

A system that detects a developing hazard and communicates an alert so that protective action can be taken.

The ground, treated as being at approximately 0 V, together with conductors electrically connected to it.

A symbolic offering made to acknowledge submission to the Persian king.

A conducting connection between the live supply and earth, allowing a potentially dangerous current to flow.

Connecting an object to Earth through a conductor so electrons can move and excess charge does not build up.

The reference electrical potential assigned to the Earth: 0 V.

Sudden ground shaking caused by the release of stored energy when rocks slip along a fault.

A building designed to withstand earthquake shaking and reduce the likelihood of collapse; it is not guaranteed to survive every earthquake.

The balance between radiation absorbed by the Earth system and thermal radiation emitted into space.

The region around Earth where a magnetic object experiences a magnetic force. Its direction and strength vary with location.

The green-and-yellow striped safety conductor that is connected to exposed metal parts in an earthed appliance and normally carries no current.

The green-and-yellow-striped safety wire connected to an appliance’s metal case. It is at earth potential (0 V) and carries current only if there is a fault.

How readily a substance starts to burn.