Combined Science key terms

A change of shape that is not completely reversed when the deforming forces are removed.

An electrically conducting electrode that does not react with the electrolyte or products during the electrolysis being considered.

(HT only) The tendency of an object to remain at rest or continue moving with uniform velocity.

(HT only) A measure of how difficult it is to change an object's velocity, defined as the ratio of resultant force to acceleration: $m = F/a$. Its unit is the kilogram (kg).

Difficulty conceiving a baby.

The movement of water from the ground surface into the soil.

An instrument that responds to infrared radiation, allowing radiation from different surfaces to be compared.

Electromagnetic radiation that transfers energy and is emitted by warm objects; it is invisible to the human eye.

A condition caused by particular alleles passed from parents to their offspring.

Unable to dissolve in water.

The speed of an object at one particular moment, rather than its average speed over an interval.

Material placed around an object to reduce energy transfer between the object and its surroundings.

A hormone released by the pancreas that lowers blood glucose concentration by causing glucose uptake by cells and storage of excess glucose as glycogen.

Reduced responsiveness of body cells to insulin.

A change between solid, liquid and gas without forming a new substance.

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. In small molecular substances, these forces are weak compared with the covalent bonds within each 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 because electrons have been lost or gained.

The strong electrostatic 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 the ions that take part in a reaction, rather than ions that remain unchanged.