Edexcel GCSE Physics key terms

Meaning carried by variations in a wave, such as the pattern representing speech in a sound wave.

Electromagnetic radiation beyond the red end of visible light, emitted by warm objects and used for heating, imaging and communication.

Sound with a frequency less than 20 Hz, below the usual range of human hearing.

The velocity at the beginning of the interval being considered, represented by $u$.

The speed of an object at one particular moment.

The power of radiation emitted per unit area; greater intensity means more energy is emitted each second from the same area.

A pair of equal-sized, opposite-direction forces of the same type that two interacting objects exert on one another.

Contamination in which radioactive material has entered the body, for example by inhalation, swallowing or through a wound.

The total energy stored by the particles in a system due to their motion and their positions relative to one another.

A relationship in which one quantity increases as the other decreases so that their product remains constant.

Describes an image that is upside down compared with its object.

An atom or molecule with an overall electric charge because it has gained or lost electrons.

The process in which one or more electrons are removed from an atom, leaving a positively charged ion.

A radiation's ability to remove electrons from atoms and form ions as it travels through matter.

Radiation energetic enough to remove electrons from atoms, which can damage cells and cause mutations.

Exposure of an object or material to radiation from a source; the source itself is not transferred.

An atom of an element with a particular number of neutrons in its nucleus.

Atoms whose nuclei have the same number of protons but different numbers of neutrons.

The unit of energy and work done.

The unit of work done and energy transferred.

A device that measures the energy transferred to a heater, in joules.

A point in a circuit where paths meet and current can split or combine.

The absolute temperature scale, beginning at absolute zero; its unit is the kelvin, K.

The energy associated with an object because it is moving.

Energy stored by an object because it is moving.

A regular arrangement of closely packed positive ions in a solid metal.

The part of the conductor that is within the magnetic field, represented by $l$ and measured in metres (m).