Triple Physics H

Radiation

Energy given out in the form of electromagnetic waves or as moving particles.

Alpha particle

A particles of two neutrons and two protons emitted by an atomic nucleus during radioactive decay.

Beta particle

Fast moving electron that is emitted by an atomic nucleus in some types of radioactive decay.

Gamma radiation

Ionising electromagnetic radiation with shortest wavelengths in the electromagnetic spectrum.

Half-life

The average time it takes for half of all the nuclei present in a sample of radioactive element ro decay, or the time it takes for the count rate to halve.

Resistance

The ratio of potential difference across an electrical component to the current through the component. Measured in ohms.

Potential difference

Measure of the energy transferred per unit charge as charges move between two points.

Current

Flow of electric charge.

Gravitational potential energy

Energy that an object has due to its position.

Kinetic energy

Energy an object has because of its movement.

Mass

Quatitiy that measures the amount of matter in an object. Measured in kg.

Power

The rate at which energy is transferred or the rate at which work is done.

Specific latent heat of vaporisation

The energy needed to change 1kg of a substance completely from a liquid to a gas without any change in temperature.

Efficiency

The useful output energy transfer divided by the total input energy transfer. May be expressed as a percentage or a decimal.

Fossil fuel

Non renewable energy source including: coal, oil, and gas.

Non renewable energy

Source of energy used by humans that will eventually run out.

Renewable energy

Source of energy that can be replaced or reused over a short period of time.

Specific heat capacity

The energy needed to raise 1kg of a substance by 1 °C. Measured in J/Kg °C.

Accuracy

How close a measurement is to its true value.

Independent variable

The quantity in an experiment that is changed or selected by the experimenter.