Edexcel GCSE Physics key terms

Radiation given out by a body, transferring energy away from it.

The capacity of a system to bring about change; energy is stored and transferred, and is measured in joules (J).

The transfer of energy from electrical cables to the surroundings by heating.

One of the particular allowed energies, represented in this model by an electron orbit at a set distance from the nucleus.

A source from which useful energy can be obtained, such as coal, wind or sunlight.

A way in which energy is held, such as a kinetic, gravitational potential, chemical or internal energy store.

The movement of energy between stores, for example mechanically, electrically or by heating.

A representation using boxes and arrows to show how energy moves between stores.

A mechanism by which energy moves between stores, such as mechanical work, electrical work, heating or radiation.

Energy moved from one store to another or transferred between systems; it is measured in joules (J).

Total energy use divided by the number of people; an average, not the amount used by every individual.

A condition in which the resultant force on an object or system is zero.

The undisturbed position about which a particle or object oscillates.

A value close enough for the intended purpose, usually found using suitable assumptions and rounded data.

The change from a liquid to a gas at the liquid's surface, which can occur below the boiling point.

A change to a higher energy level after energy has been absorbed.

A nucleus left with excess energy, often following another radioactive decay.

A temporary higher-energy condition of an atom after one of its electrons has absorbed energy and moved to a higher energy level.

An increase in the volume occupied by a gas.

The increase over time in the distances between widely separated galaxies as space expands.

A decrease in which the amount lost per unit time becomes progressively smaller, producing a curved graph.

The increase in an object's length, calculated as stretched length minus original length.

Treatment in which high-energy radiation beams are directed at a tumour from equipment outside the body.

Contamination on the surface of an object or the outside of the body.

A force exerted on the chosen object or system by something outside its boundary.

A current that flows along an unintended path because of a fault in an electrical system.

A material, such as iron, cobalt or nickel, that responds strongly to a magnetic field and can itself be magnetised.