OCR GCSE Chemistry B key terms

A diagram that uses dots and crosses to distinguish the outer-shell electrons supplied by different atoms and show how electrons are shared in covalent bonds.

A covalent bond in which two atoms share two pairs of electrons.

A covalent bond containing two shared pairs of electrons.

Able to be drawn into a wire.

The state reached in a closed system when the forward and reverse reactions continue at equal rates, so the concentrations of reactants and products remain constant.

A factor concerning money or resources, such as purchase price, running costs, affordability, employment or the cost of taking action.

A line where two faces of a solid meet; for a cube, every edge has the same length.

A measure of how readily a material allows electric current to flow through it.

A conductor through which current enters or leaves an electrolyte; in electrolysis, the anode is positive and the cathode is negative.

The breakdown of an ionic substance by passing direct electric current through it when molten or dissolved in water.

A liquid containing mobile ions that can carry charge between electrodes.

A negatively charged subatomic particle, represented in an equation by $e^-$.

The distribution of an atom's electrons between its electron shells.

A region around an atomic nucleus in which electrons are arranged.

The movement of one or more electrons from one atom to another when ions form.

The attraction between particles with opposite electric charges.

A force between electrically charged particles; opposite charges attract and like charges repel.

A pure substance made from only one type of atom.

The release of energy from matter as electromagnetic radiation.

An instrumental technique that identifies elements by analysing the wavelengths of light emitted by a hot sample.

A pattern of light emitted at particular wavelengths by a hot sample.

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

The management of a product when it is no longer useful, which may include reuse, recycling, incineration or landfill.

A reaction direction that takes in energy from the surroundings, usually as heat.

A reaction that transfers energy from the surroundings to the reacting chemicals, usually causing the surroundings to cool down.

The stage in a titration at which the indicator undergoes its chosen colour change.

An observable point chosen to stop timing a reaction, such as a specified colour change.

A factor concerning the natural world, such as resource use, waste, pollution, habitats or long-term sustainability.