Edexcel GCSE Chemistry key terms

A thick crude oil fraction used as a surfacing material for roads and roofs.

The removal of colour from a substance by a chemical reaction.

The physical change from a liquid to a gas throughout the liquid at its boiling point.

The temperature at which a liquid boils and changes into a gas.

The separation of particles that were joined by a chemical bond; energy must be supplied for this to happen.

The energy required to break one mole of a specified covalent bond, usually stated in kilojoules per mole.

A pair of electrons shared between two atoms; it represents one covalent bond.

The formation of a chemical bond between particles; this releases energy.

Likely to fracture with little bending or other deformation when a force is applied.

The tendency to fracture with little bending or permanent deformation.

An orange solution of bromine in water, used to test for a carbon–carbon double bond.

A material considered as a much larger piece rather than as nanoparticles.

A graduated tube with a tap that delivers a measured volume of solution.

A substance formed alongside the desired product in a reaction.

A spherical fullerene molecule containing 60 carbon atoms, also called buckminsterfullerene.

A graph that relates instrument readings to known concentrations of a substance.

An insulated container used to measure temperature changes caused by a physical or chemical change.

An experiment that measures an energy change indirectly from a measured temperature change.

An ion with the formula $\mathrm{CO_3^{2-}}$. It produces carbon dioxide when treated with dilute acid.

A rock containing calcium carbonate; limestone and marble are important examples.

Solid material containing carbonate ions that settles and can eventually become part of sedimentary rock, storing carbon for a long time.

A gas made of carbon and oxygen, with the formula $CO_2$. It was present in a large amount in the Earth's early atmosphere.

A compound with the formula CO, formed when carbon is only partly oxidised.

The extraction of a metal from its compound by heating it with carbon or using a carbon-derived reducing agent such as carbon monoxide.

A stable compound formed when carbon monoxide binds strongly to haemoglobin.

An organic compound containing the –COOH functional group.

A substance that increases the rate of a chemical reaction without altering its products and is unchanged chemically and in mass at the end of the reaction.