Chemistry key terms

A substance added to dissolve aluminium oxide and lower the temperature needed for electrolysis.

The formation of solid crystals from a solution, usually after concentrating the solution and allowing it to cool.

A three-dimensional shape with six identical square faces and edges of equal length.

A measurement unit raised to the power 3, used for volume; for example, cm³.

A smooth line or curve that represents the overall pattern of experimental data without necessarily passing through every point.

A drawing convention in which an ordinary line represents a bond in the plane of the page, a solid wedge points towards the viewer and a dashed wedge points away.

Information presented as measurements, counts or observations so that it can be examined and interpreted.

A plotted mark representing one pair of values from a results table.

An organised arrangement of data in labelled rows and columns.

Changing information from one representation, such as a table, into another representation, such as a graph, while preserving its meaning and values.

A place to the right of the decimal point. Decimal places are counted from the decimal point, not from the first non-zero digit.

The number of digits written after the decimal point.

A choice reached after considering available evidence, arguments, risks, benefits and relevant circumstances.

To remove the colour from a substance during a chemical change.

The chemical splitting of a compound into simpler substances.

A sign of poor plant growth caused by an insufficient supply of a needed nutrient.

The fraction or percentage of acid particles that form ions when the acid dissolves in water.

A reaction in which water is removed from a substance.

Water from which dissolved ions have been removed.

An electron that is not confined to one bond and can move through part of a structure.

Electrons that are not tied to one atom or one bond and can move through a structure.

The level of desire or need for a product.

A change in an enzyme's shape caused by excessive heat, so its active site can no longer catalyse the reaction effectively.

Mass per unit volume. A denser material contains more mass in the same volume.

The variable measured in response to the change in the independent variable.

The physical change directly from a gas state to a solid state, without passing through the liquid state.

A visual clue, such as overlap, relative position or angled bonds, that helps a flat image represent depth.

A quantity found from other measured quantities using a defined relationship or equation.

The removal of dissolved salts from salty water or seawater.

A model expressed in words or statements that explains how a system behaves.