Edexcel GCSE Chemistry key terms

A simplified representation used to describe or explain something that is difficult to observe directly.

Discarded metal that can be collected and processed for recycling.

The settling of insoluble particles to the bottom of a liquid when it is left still.

The ability of a test to detect a small quantity of a substance or a small change in its amount or concentration.

A pair of electrons associated with both bonded atoms rather than with only one of them.

The reduction in the nucleus’s attraction for an outer electron caused by electrons in inner shells.

An atom or group attached to the polymer backbone rather than forming part of the continuous backbone itself.

A competing reaction that consumes reactants and forms an unwanted product instead of some of the desired product.

The number of meaningful digits used to express the precision of a measured or calculated value.

A method of separating a liquid from a mixture by boiling it and then condensing its vapour.

A single charged atom formed when an atom gains or loses electrons.

A substance made of separate, small molecules in which non-metal atoms are joined by covalent bonds.

A substance containing separate, relatively small molecules with covalent bonds within each molecule.

A covalent bond containing one shared pair of electrons.

Easy to cut or deform; alkali metals are soft enough to be cut with a knife.

A state of matter in which particles are closely packed in a regular arrangement and vibrate about fixed positions.

The ability of a substance to dissolve in a particular solvent.

A rule used to predict whether an ionic compound will dissolve in water.

Able to dissolve in water to form a solution.

A salt that dissolves in water to form an aqueous solution.

The substance that is dissolved to form a solution.

A mixture formed when a solute dissolves in a solvent.

A substance in which a solute dissolves.

The furthest position reached by the solvent on the chromatography paper.

Fine particles of solid carbon produced during some incomplete combustion reactions.

An atom, ion or molecule involved in a chemical reaction.

An ion that is present but remains unchanged during a reaction.