OCR GCSE Combined Science A key terms

A substance that neutralises an acid. Metal oxides and metal hydroxides are examples.

The starting line on a chromatogram where the samples are placed.

Sampling organisms within quadrats along a line to investigate how their abundance changes with position. Quadrats may be placed at regular intervals.

A change in shape in which an object becomes curved because forces act at different points.

A non-cancerous tumour that remains contained in one area.

An electron emitted from a nucleus when a neutron changes into a proton, represented by $^{0}_{-1}\mathrm{e}$.

An electron emitted from a nucleus when a neutron changes into a proton during beta-minus decay.

A systematic tendency for a method to favour particular observations, making the results unrepresentative.

A disc shape with a depression on both sides, giving a large surface area relative to its volume.

A compound containing just two different elements.

A compound containing exactly two different elements, held together by the attraction between oppositely charged ions.

The variety of living organisms in an area.

A fuel made from recently living material, such as plant matter, ethanol or methane produced from organic material.

The use of bacteria to convert metal compounds in ores into soluble forms, producing a solution containing metal ions.

The mass of living material in an organism or group of organisms.

A living component of an ecosystem, such as a plant or animal.

An influence of living organisms on other organisms, such as predators or the availability of food.

A large industrial furnace in which iron is extracted from iron ore using carbon monoxide produced from coke.

The removal of colour from a substance; chlorine bleaches damp litmus paper white.

The amount of glucose in a given volume of blood.

The liquid part of blood in which hormones are transported.

The change of state from a liquid to a gas throughout the liquid, with bubbles of gas forming.

The temperature at which a substance boils or condenses, at a given pressure.

The mean energy needed to break one mole of a particular type of chemical bond, measured in kJ/mol.

The distance between the nuclei of two bonded atoms.

The distance a vehicle travels from when the brakes are applied until it comes to rest.

An alloy of copper and zinc.