Physics key terms

The path an object follows around another object in space.

The time taken for an orbiting body to complete one orbit.

The distance from an orbiting object to the centre of the body it orbits.

How fast an object moves along its orbit.

The power of ten that represents the approximate scale of a quantity.

A changing current that repeatedly reverses or varies in size and can produce radio waves.

A repeated movement or change about a central position or value.

An instrument that displays how an electrical signal varies with time.

Three small bones that carry vibrations from the eardrum towards the inner ear.

The electrons in an atom's highest occupied electron shell; these are the electrons lost when the positive ions considered here form.

A result that lies noticeably away from the pattern formed by the other data.

The potential difference measured between two selected points in a sensing circuit.

A pair consisting of the force of object A on object B and the force of object B on object A, produced by one interaction.

An apparent shift in a reading caused by viewing a scale from an angle rather than straight on.

A circuit arrangement containing separate branches that provide more than one route for current.

A circuit containing separate branches that provide more than one path for current.

The original unstable nucleus in a nuclear change.

A small unit used in the particle model to represent matter, such as an atom or molecule.

A simplified scientific representation in which matter is treated as particles, such as atoms or molecules.

The speed and direction in which a particle is moving. Gas particles have continually changing velocities because their motion is random and collisions alter their directions.

The standard unit of pressure, equal to one newton per square metre (N/m²).

The SI unit of pressure; one pascal is equal to one newton per square metre.

The wavelength at which an object's emitted radiation has its greatest intensity.

The checking of scientific findings by other scientists, who assess whether the methods, evidence and conclusions are sound.

A radiation's ability to travel through matter before being absorbed or losing enough energy to stop.

How readily radiation passes through a material before being absorbed.

How likely a person believes harm to be; this may differ from a statistical estimate.