Combined Science key terms

The process by which a cell becomes specialised to carry out a particular function.

The net movement of particles from a region of higher concentration to a region of lower concentration.

The distance a substance travels by diffusion between two regions.

The breakdown of large, insoluble food molecules into small, soluble molecules that can be absorbed.

A solution containing relatively little dissolved solute and a relatively high concentration of water.

A component that allows current to flow in one direction only and has a very high resistance in the reverse direction.

Describes a cell or nucleus containing two sets of chromosomes, one inherited from each parent.

An electric current that flows in one direction only.

An electric current in which charge moves in one direction only.

A potential difference whose polarity stays the same: the positive and negative terminals do not swap.

A relationship in which multiplying one quantity by a factor multiplies the other by the same factor. For constant gravitational field strength, $W \propto m$.

A relationship in which multiplying one quantity by a factor multiplies the other by the same factor, written $y \propto x$.

A potential difference whose polarity remains the same: the positive and negative terminals do not exchange roles.

The number of new cases of a disease in a population over a stated time period, often expressed relative to population size.

The separation of light into its constituent colours because different wavelengths travel at different speeds in a material and are refracted by different amounts.

The straight-line change in position from the starting point to the finishing point, including direction; a vector quantity.

A reaction in which a more reactive element replaces a less reactive element in a compound.

A representation showing every atom and every covalent bond in a molecule.

The spreading of energy into the surroundings, where it becomes less useful.

The separation of a substance into ions when it dissolves; an acid dissociates to produce hydrogen ions.

The process in which a substance mixes into a liquid to form a solution.

The total length of the path travelled by an object. It is a scalar quantity.

A graph showing the total distance travelled by an object against elapsed time, with distance on the vertical axis and time on the horizontal axis.

The liquid collected after vapour condenses during distillation.

A separation process in which a liquid is vaporised and its vapour is cooled and condensed so that the liquid can be collected.

A change in an object's shape caused by forces, such as stretching, bending or compression.

Something that draws attention away from the task being carried out.