Key terms & definitions

A small heat-resistant container used to heat a solid strongly.

A cross bearing a representation of Jesus Christ.

A cross bearing a figure of the crucified Jesus.

Jesus’ execution by being nailed to a cross.

A church building or layout shaped like a cross.

The number of births during a stated period per specified number of people in the total population, commonly per 1000 people.

The number of deaths during a stated period per specified number of people in the total population, commonly per 1000 people.

A liquid fossil fuel formed from the remains of ancient organisms over millions of years, which can be refined into fuels and other petroleum products.

A naturally occurring fossil fuel that is a complex mixture of hydrocarbons.

A liquid mixture of hydrocarbons formed over millions of years from buried remains of plankton.

A naturally occurring mixture extracted from underground and refined to provide chemical starting materials for polymers such as acrylic, HIPS and ABS.

A rate calculated for a whole population without adjusting for differences in its composition, such as its age distribution.

A part of a car designed to deform in a collision, increasing the time taken for the car to stop.

Parts at the front and back of a car designed to crumple in a collision. They increase the time taken for the car to stop, which reduces the rate of change of momentum and so the force on the people inside.

A religious military expedition authorised by the pope; the Third Crusade aimed to recover Jerusalem for Christian rule.

A person who committed to a religiously authorised expedition, represented by wearing a cross on their clothing.

One of the territories established by Latin Christian rulers in the eastern Mediterranean following the First Crusade: Edessa, Antioch, Tripoli or Jerusalem.

Territories established and ruled by Christian lords after conquest during the crusades.

A series of medieval religious wars involving Christians and Muslims, fought primarily over Jerusalem and other holy sites.

A commitment to defending and extending Christianity, which could motivate warfare and expansion.

The thin, solid outer layer of the Earth, made of rock.

A substance added to dissolve aluminium oxide and lower the temperature needed for electrolysis.

A substance in which aluminium oxide is dissolved during aluminium extraction, forming an electrolyte with a lower melting point than pure aluminium oxide.

The formation of solid crystals from a solution, usually after concentrating the solution and allowing it to cool.

The formation of an ordered solid crystal structure from a liquid or solution.

Obtaining a dissolved solid as crystals from a solution.

A range of envelope sizes designed to hold the corresponding A-series paper unfolded, such as C4 for A4.

A computed tomography scan: a technology that uses X-rays to produce detailed images of the inside of the body.

A technique that uses multiple X-ray measurements and computer processing to produce images of structures inside the body, including the brain.

A computerised tomography scan: an imaging technique that combines X-ray views to produce detailed cross-sectional images of brain structure.