AQA GCSE Chemistry key terms

The corrosion of iron or steel when both oxygen from the air and water are present.

Protection in which a more reactive metal corrodes instead of the metal being protected.

An ionic compound containing positive ions and negative ions, with no overall electrical charge.

A solution in which no more solute can dissolve at that temperature.

A simplified representation used to describe and explain scientific observations; it may be changed or replaced when new evidence does not fit it.

A proposed explanation of events or observations that can be assessed using evidence.

Particles of solid material that settle and accumulate, often on the floor of a body of water.

Rock formed when layers of sediment accumulate and become compacted or cemented together.

The settling of suspended solid particles under gravity.

A life cycle assessment that includes only selected stages or environmental effects.

The ability of a method to detect or measure a very small amount of a substance.

Waste water containing human waste and other material carried away from homes and other buildings.

The thick, solid-rich material that settles at the bottom of a sedimentation tank.

The reduction in the attraction between the nucleus and an outer electron caused by electrons in inner shells.

A change in the position of equilibrium towards reactants, increasing their relative amount at the new equilibrium.

A change in the position of equilibrium towards products, increasing their relative amount at the new equilibrium.

A reaction other than the expected reaction that uses some reactant and forms different products.

Separating a solvent from a solution by boiling it and then cooling its vapour to collect the liquid.

A simplified representation in which small spheres stand for the atoms, ions or molecules in a substance.

A discrete group of a relatively small number of atoms held together by covalent bonds.

An ionic compound that dissolves in water to form a solution containing mobile ions.

A substance that dissolves in a solvent to form a solution.

A mixture formed when a solute dissolves in a solvent.

A liquid in which a solute dissolves.

The furthest point reached by the solvent on the stationary phase.

A solid particle of carbon produced during incomplete combustion of a carbon-containing fuel.

An atom, ion or molecule taking part in a chemical reaction.

An ion that remains unchanged during a reaction and does not appear in the ionic equation.