Combined Science key terms

The amount of substrate in a given volume of solution.

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

A gas, $\mathrm{SO_2}$, that causes respiratory problems and contributes to acid rain.

The total area of a solid exposed to its surroundings and available for contact with another reactant.

The surface area of an object divided by its volume. Smaller pieces of the same shape have a larger surface area to volume ratio.

The surface area of an organism or object compared with its volume, calculated by dividing surface area by volume.

Water flowing over the land surface towards streams, rivers, lakes and the sea.

Everything outside the reacting chemicals that can exchange energy with them, such as the surrounding solution, container and air.

How likely an individual is to develop a disease.

Using resources in a way that allows them to remain available for future generations.

Development that meets the needs of current generations without compromising the ability of future generations to meet their own needs.

A device that opens or closes a conducting path in a circuit.

A representation of a chemical reaction using the chemical symbols and formulae of the reactants and products.

A change in the body caused by a disease, such as pain or fever.

A junction between neurones containing a tiny gap across which neurotransmitters carry the signal.

The building of larger molecules from smaller molecules through chemical reactions.

A product manufactured through chemical processes rather than obtained in its final form directly from nature.

An object or group of objects chosen for study.

A straight line that touches a curve at a chosen point and has the same slope as the curve there.

An organ that responds to a particular hormone.

The formation of a dull surface coating when a metal reacts with substances in the air.

A measure related to the average kinetic energy of the particles in a substance.

The final temperature minus the initial temperature, written $\Delta\theta$ and measured in degrees Celsius.

A gradual change in temperature with position, such as the decrease in temperature up a fractionating column.

The ability of a material to resist breaking when it is stretched or pulled.

The pulling force exerted on an object by a stretched rope, string or cable, acting along it.

The constant velocity reached by a falling object when the forces balance and its acceleration becomes zero.