AQA GCSE Combined Science Trilogy key terms

The dependence of organisms on one another for resources or services, such as food, shelter and maintaining their environment.

An attractive force between separate molecules, rather than a bond between atoms within a molecule.

The total kinetic and potential energy of the particles making up a system.

A small contraceptive device fitted inside the uterus; it may be non-hormonal or release a hormone.

A relationship in which multiplying one quantity by a factor divides the other by that factor.

Higher Tier: a relationship in which a quantity is proportional to the reciprocal of distance squared. For light intensity, $I \propto 1/d^2$.

Fertilising an egg with sperm outside the body, in a laboratory, before transferring an embryo into the womb.

An atom or group of atoms with an overall electrical charge.

The strong electrostatic force of attraction between oppositely charged ions.

The strong electrostatic attraction between oppositely charged ions, acting in all directions throughout an ionic lattice.

A compound consisting of positive and negative ions held together in a giant structure by strong electrostatic attraction.

An equation showing only the particles involved in the chemical change, with unchanged spectator ions omitted.

The production of charged particles called ions. Nuclear radiation can ionise atoms by knocking electrons out of them.

Radiation with enough energy to remove electrons from atoms, forming ions. X-rays and gamma rays are ionising radiation.

The process of exposing an object to nuclear radiation. The irradiated object does not become radioactive.

Atoms of the same element with the same number of protons but different numbers of neutrons.

A graph showing how the current through a component varies with the potential difference across it.

In vitro fertilisation: a fertility treatment in which eggs are fertilised by sperm in a laboratory and an embryo is transferred into the uterus.

The unit of energy and work done. One joule is the work done when a force of one newton causes a displacement of one metre along its line of action.

A point where circuit branches meet and current can split or recombine.

Energy stored by a moving object. It depends on its mass and the square of its speed: $E_k = \frac{1}{2}mv^2$.

Energy stored by a moving object.

A substance formed by the incomplete oxidation of glucose during anaerobic respiration in muscles.

A site where waste is disposed of by burying it in the ground.

Energy transferred when a substance changes state without changing temperature.

A light-dependent resistor: an electrical component whose resistance decreases as the light intensity reaching it increases.

A solution containing substances dissolved out of a solid material; in bioleaching, it contains dissolved metal compounds.