Edexcel GCSE Chemistry key terms

The production of gas bubbles during a reaction.

The ability of a material to allow electric current to pass through it.

A substance that allows electric charge to flow through it.

A material through which electric current does not flow easily.

A conductor through which electrical charge enters or leaves a cell.

The decomposition of an ionic compound by passing a direct electric current through it while it is molten or dissolved.

A substance containing mobile ions that can carry charge within a cell.

The use of electrolysis to remove impurities from a metal.

A subatomic particle surrounding the nucleus with a relative charge of −1.

The arrangement of electrons in the shells around an atom's nucleus.

A region around an atomic nucleus that electrons occupy; it is also called an energy level.

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

The movement of one or more electrons from one atom to another during a reaction.

The process of using electrolysis to deposit a thin layer of one metal on the surface of an object.

The attraction between particles with opposite electric charges.

The force of attraction or repulsion between electrically charged particles.

A substance made from only one type of atom; it may contain single atoms or molecules of that element.

A pattern of light at particular wavelengths produced by a substance; each metal ion produces a characteristic emission spectrum.

The simplest whole-number ratio of atoms of each element in a compound.

The sum of the relative atomic masses represented by one empirical formula unit.

A reaction or change that takes in heat energy from the surroundings.

A change or reaction in which heat energy is taken in from the surroundings.

A reaction in which heat energy is taken in from the surroundings because breaking reactant bonds requires more energy than forming product bonds releases.

The point in a titration at which the indicator changes to the colour showing that the required reaction has just occurred.

The energy transferred overall during a chemical reaction; it equals the energy needed to break bonds minus the energy released when new bonds form.

The movement of energy from one place or set of substances to another; energy is not created or destroyed.

A control that physically separates people from a hazard, such as a fume cupboard or safety screen.