Combined Science key terms

A measure combining two quantities, such as distance divided by time, expressed in units such as mm/min.

A region of a longitudinal wave where the particles of the medium are closer together than usual.

A solution containing a relatively large amount of dissolved substance per unit volume.

The amount of a dissolved substance per unit volume of solution.

A difference in the concentration of a substance between two regions.

The change of state from gas to liquid.

Energy transfer through a material from hotter regions to colder regions without the material moving overall.

A material through which electric charge can flow.

The protection and careful management of species and habitats to maintain biodiversity.

The rule that the total current entering a circuit junction equals the total current leaving it.

The principle that energy cannot be created or destroyed, only transferred. The total energy before and after a chemical reaction is the same.

The principle that the total mass of all reactants equals the total mass of all products in a chemical reaction: atoms are rearranged, not created or destroyed.

The principle that, in a closed system, total momentum before an event equals total momentum after the event.

A mass that no longer changes after repeated heating, cooling and weighing; in the magnesium oxide experiment, this indicates that the reaction is complete.

A speed that does not change: equal distances are travelled in equal time intervals.

An organism that obtains food by eating other organisms.

A force between objects that are physically touching.

A method in which small samples are repeatedly removed from a reaction mixture to monitor its progress.

A method used to prevent pregnancy.

A factor kept constant so that its effect does not interfere with the investigation.

The direction of electric current defined as the direction positive charge would flow: from the positive terminal to the negative terminal through the external circuit.

A part of a control system that receives and processes information from receptors, such as the brain, spinal cord or pancreas.

A blood vessel that supplies the heart muscle with blood containing oxygen and glucose.

A disease in which layers of fatty material build up inside the coronary arteries, narrowing them and reducing the supply of oxygen to the heart muscle.

The structure formed from the follicle left in an ovary after ovulation; it produces progesterone.

A relationship between two variables in which changes in one are associated with changes in the other. It does not, by itself, establish that one causes the other.

Describes a substance that can attack living tissue, causing chemical burns and serious eye damage.