Key terms & definitions

The arrangement of atoms and the bonds connecting them in a substance.

A one- or two-letter abbreviation used to represent an element and its atoms.

A one- or two-letter representation of an element, such as O for oxygen or Na for sodium. It can also represent one atom of that element.

A chemical used to identify another substance through an observable change.

A weapon that uses toxic chemicals to poison or injure people.

The breakdown of rock through chemical reactions that change or dissolve its minerals.

The treatment of cancer using drugs that kill cancer cells or slow their growth.

A soft, fluffy novelty yarn with short fibres projecting from a central core.

Loving-kindness: care for others expressed through compassionate actions.

The space within the rib cage containing the lungs and heart. Its volume changes during breathing.

A destructive raid intended to weaken an enemy by burning crops, plundering settlements and terrorising the population.

A Jewish burial society that prepares the deceased for burial with dignity and helps families follow Jewish burial customs.

A Jewish burial society whose members prepare the dead for burial with care and respect.

A strong contrast between light and darkness within an image.

A reversal of words or ideas in successive phrases, as in Leonato’s contrast between weeping at joy and finding joy in weeping.

A term adopted by many Mexican American activists to express pride in their identity and support for political, social and cultural rights.

The most senior council officer and head of its paid staff, responsible for managing operations and implementing councillors’ decisions.

The monarch’s leading adviser and organiser of government, whose authority depended on royal favour.

A family in which children’s care, education, safety and happiness are central priorities.

An approach to education that takes account of learners' abilities, interests and developmental needs.

Work that children are too young to do, or that harms their health, development or ability to learn, play and rest.

The employment of children, often in demanding or dangerous work that limits their opportunities for education.

The ways parents or carers bring up children, including providing care, setting boundaries, teaching behaviour and offering emotional support.

A young person employed or compelled to serve in a household. Some wealthy households in early modern Britain kept African or Indian child servants.

Low height for a child's age, indicating longer-term undernutrition.

Low weight for a child's height, indicating undernutrition.

Storing food at 0°C to below 5°C to slow the growth of microorganisms.

An artificial raised agricultural plot constructed in shallow lake water, used to grow crops.

Productive raised agricultural fields constructed in shallow lake or wetland areas, with canals between them.

A manufactured board made from wood chips or shavings bonded with adhesive and compressed into sheets.