AQA GCSE Combined Science Trilogy key terms

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 withstand stretching forces without breaking.

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.

A consumer that eats a secondary consumer.

The main male reproductive hormone, produced by the testes; it stimulates sperm production.

An arrangement in which four neighbouring atoms surround a central atom in three dimensions, towards the corners of a tetrahedron.

Producing an embryo with the same genes as a patient so that its stem cells can be used for treatment without being rejected by the patient’s body.

The transfer of energy from a hotter region to a cooler region through a material, without the material flowing as a whole.

The ability of a material to transfer energy through itself by heating.

A reaction in which a substance breaks down into simpler substances when heated.

The increase or decrease in a material’s thermal energy store as its temperature changes, measured in joules.

An energy store associated with the particles of an object. Increasing this store can raise the object’s temperature.

An increase in the volume of a substance as its temperature rises.

Producing an image from infrared radiation emitted by objects, revealing differences in their temperature.

Using insulating materials to reduce the rate of energy transfer by heating.

An electrical component whose resistance changes with temperature. For the thermistors studied here, resistance decreases as temperature increases.

A device that controls heating or cooling to maintain a chosen temperature.

The distance a vehicle travels during the driver's reaction time, before the brakes are applied.

Two equal and opposite forces of the same type, exerted by two interacting objects on each other. Each force acts on a different object.

A cable containing three separately insulated conducting wires: live, neutral and earth.

A hormone released by the thyroid gland that stimulates basal metabolic rate and supports growth and development.