AQA GCSE Combined Science: Synergy key terms

To express something as a numerical quantity, such as energy used in megajoules or waste produced in kilograms.

A measure of the risk of harm resulting from exposure of the body to radiation, measured in sieverts (Sv).

The unwanted presence of radioactive material inside, or on the surface of, another material.

The spontaneous change of an unstable atomic nucleus, accompanied by the emission of nuclear radiation.

An isotope with unstable nuclei that can decay by emitting radiation.

Material containing unstable atoms whose nuclei emit radiation as they decay.

An electromagnetic wave that can be produced by electrical oscillations and can induce electrical oscillations when absorbed.

The distance from the centre of a circular or spherical object to its outer edge; half its diameter.

Assigning participants to treatment groups by chance rather than by deliberate selection.

An unpredictable variation between readings that causes results to scatter.

The continuous movement of particles in many different directions, with no overall preferred direction.

The unpredictable decay of individual unstable nuclei: it is not possible to know which nucleus will decay next or exactly when it will decay.

Selecting sampling locations by chance rather than by personal choice, reducing selection bias.

A region of a longitudinal wave where the particles of the medium are further apart.

The amount of photosynthesis occurring per unit time, estimated experimentally using measures such as oxygen production.

The amount of reactant used up or product formed per unit time.

A line representing the direction in which a wave travels, with an arrowhead showing that direction.

A starting substance that takes part in a chemical reaction.

The substances mixed together in which a chemical reaction takes place.

A diagram showing how energy changes as reactants are converted into products, including the activation energy barrier.

The time between noticing a stimulus, such as a road hazard, and responding to it.

An arrangement of elements in order of reactivity. Carbon's position can be used to predict which metal oxides it can reduce.

A chemical added to a sample to produce a reaction or change that helps identify a substance.

Pouring a melted material into a mould and allowing it to solidify into a new shape.

A cell that detects a stimulus.

An allele expressed only when two copies are present and no dominant allele is present in the simple two-allele inheritance model.

Processing a waste material so that it can be used to make a new product.