AQA GCSE Chemistry key terms

A notation written after a chemical formula to show the physical state of that substance in a chemical equation.

The material that remains in place while chromatography is carried out; in paper chromatography, this is the paper.

An alloy of iron containing controlled amounts of carbon and, in some types, other elements.

Treatment that kills microorganisms in water, for example using chlorine, ozone or ultraviolet light.

The quantitative relationship between the amounts of reactants and products in a balanced chemical equation.

The ability of a material to withstand forces without breaking or permanently changing shape.

An acid that is completely ionised in aqueous solution.

A small number written after and below an element symbol or bracket, showing how many of those atoms or groups are present.

A collision between reacting particles that has enough energy for a reaction to occur.

A negatively charged ion with the formula $\mathrm{SO_4^{2-}}$.

The total area of a solid exposed to its surroundings.

The amount of exposed surface of a solid compared with its volume.

The area or materials around the reacting substances to which energy can be transferred or from which energy can be taken.

Development that meets the needs of current generations without compromising the ability of future generations to meet their own needs.

A manufactured material or product made by chemical processes rather than obtained directly in its final form from nature.

A straight line drawn at a chosen point on a curve that follows the curve’s direction there. Its gradient shows the rate of change at that point.

The difference between the final and initial temperatures, measured in °C in these investigations.

A material's ability to withstand a pulling force without breaking or stretching excessively.

The maximum amount of product predicted from the balanced equation, assuming the relevant reactant forms the expected product without losses.

A material through which thermal energy is transferred readily.

A polymer with strong cross-links between its chains, so it does not melt when heated.

A polymer whose separate chains can move past one another when heated, allowing the material to melt and be reshaped.

A method for measuring the volumes of two solutions that react together by adding one solution to a measured volume of the other until an indicator changes colour.

The volume delivered from the burette during a titration, found by subtracting its initial reading from its final reading.

A metal in the central region of the periodic table; many transition elements form ions with different charges, form coloured compounds and are useful as catalysts.

A general pattern showing how a property changes across a series of elements.

Cloudiness caused by fine particles suspended in a liquid.