AQA GCSE Combined Science: Synergy key terms

A small mesh tube placed inside an artery to hold it open and improve blood flow.

A device that decreases the potential difference of an alternating electrical supply.

A device that increases the potential difference of an alternating electrical supply.

Treatment that kills microorganisms; in drinking-water treatment it prevents harmful microorganisms from causing disease.

A change in the internal or external environment that can be detected and produce a response.

The quantitative relationship between the amounts of reactants and products in a chemical reaction, expressed by the mole ratios in its balanced equation.

A tiny pore in the surface of a leaf through which gases and water vapour can diffuse. The plural is stomata.

The total distance a vehicle travels from the driver first noticing the need to stop until the vehicle comes to rest; thinking distance plus braking distance.

A lamp that flashes repeatedly at an adjustable frequency and can make a repeating movement appear stationary.

An acid that is completely ionised in aqueous solution.

A particle smaller than an atom that forms part of its structure, such as an electron, proton or neutron.

A particle smaller than an atom that forms part of its structure, such as a proton, neutron or electron.

A structure within a cell that carries out a particular function.

A change directly from solid to gas, without passing through the liquid state.

A small number written below the line in a chemical formula, showing the number of atoms of the preceding element or the number of repetitions of the preceding bracketed group.

A reactant that binds to an enzyme’s active site.

A collision between reacting particles that results in a chemical reaction.

A gas, $\mathrm{SO_2}$, produced when sulfur-containing fuels burn. It causes respiratory problems and contributes to acid rain.

The total area of the exposed outer surfaces of an object or collection of pieces.

The surface area of an object divided by its volume. A larger value means more exposed surface per unit volume.

The total area of an object's surface compared with its volume, calculated as surface area divided by volume and commonly written as $x:1$.

Everything outside the reaction mixture that can exchange energy with it, including the container and nearby air.

Using resources at a rate that allows them to be renewed, so they remain available in the future.

An effect of a disease experienced by the affected person, such as pain, tiredness or a headache.

A junction between neurones with a tiny gap across which chemicals transmit the signal.

The building of larger molecules by joining smaller molecules together.

An object or group of objects chosen for study.