Physics Words
- Electron The negatively charged particle in an atom
- Emit The process of giving out radiation
- Energy The ability of an object to do work. Measured in Joules.
- Energy source Something that you can use to generate energy, e.g. coal, wind power
- Evaporation When a substance changes from a liquid to a gas
- Extension (of a spring) How much a spring changes in length by when a force is applied.
- Filament lamp A light bulb - it works by heating up a small "filament" (wire) inside the bulb
- Filtration An insoluble solute is separated from a solvent using filtration
- Fission A process that splits the nucleus of an atom into smaller nucleii and releases energy
- Fluid A general name for a liquid or a gas
- Fluorescent When a substance can absorb radiation and then re-emit it as light, such as fluorescent paint
- Focal length The distance between the focus and the point where the converging rays meet.
- Focus The point a converging lens will focus parellel rays of light onto.
- Force A push or a pull
- Free electrons Electrons that are free to move around and carry current or heat
- Freezing When a substance changes from a liquid to a solid.
- Frequency The number of waves or events per second
- Friction A force that opposes motion
- Fuel A substance that can be grown and then burnt to release energy, e.g. wood
- Fuse A safety device in a plug that melts if the current through it is too high
- Galaxy A group of billions of stars
- Gamma radiation One of the three forms of ionising radiation, along with beta and alpha
- Gas One of the three states of matter, along with solid and liquid
- Gas-fired power station A power station that burns gas (a fossil fuel) in order to generate electricity
- Geiger counter A device used to measure the amount of radiation given out by a radioactive substance
- Geiger-Muller tube A device used to measure the amount of radiation given out by a radioactive substance
- Generator A device used to generate electricity when it turns
- Geothermal energy A source of energy - when hot rocks underneath the Earth are used to heat water
- Giga An abbreviation meaning "1,000,000,000"
- Graviational potential energy The potential energy an object has due to the action of gravity on it
- Gravitational field strength The strength of a planet's gravitational field - symbol g
- Gravitational potential energy The potential energy an object has due to the action of gravity on it
- Gravity A force that pulls objects together
- Half life The time it takes for half of the isotopes in a sample to decay or for the radioactivity of a sample to halve.
- Heat transfer The flow of heat energy from a hotter area to a colder area
- Hertz The unit of frequency - 1Hz is equal to "1 event per second"
- Hooke's Law A law that states that, for any material being stretched, the extension of the material is proportional to the applied force.
- Hydroelectricity Electricity that is generated using water falling through a dam - a renewable energy source
- Hz The unit of frequency - 1Hz is equal to "1 event per second"
- Induced magnet A temporary magnet that has been "made" using a permanent magnet
- Inelastic deformation When a material is stretched so that, when the force is removed, it no longer returns to its original shape.
- Inertia The property of a body that means it wants to keep doing what it was doing.
- Inertial mass Force divided by acceleration.
- Infra red An electromagnetic wave that transfers heat energy
- Insulation A material that is poor at conducting heat or electricity
- Insulator A material that is poor at conducting heat or electricity
- Ionisation A process where an atom gains or loses an electron to form an ion
- Ionising radiation Alpha, beta or gamma radiation or any radiation (e.g. X-rays) that can cause ionisation.
- J Short for the unit "Joule", the unit for energy
- Joule The unit for energy
- Kilo An abbreviation meaning "1,000"
- Kilowatt 1,000 Watts
- Kilowatt hour A unit for measuring electricity, sometimes simply called "units"
- Kinetic energy Also called movement energy - the energy an object has when it is moving
- KW An abbreviation for kilowatt. 1KW = 1,000 Watts
- KWh An abbreviation for "kilowatt hour", a unit for electrical energy
- Life cycle of a star The cycle a star goes through from its formation to its death.
- Light Dependent Resistor (LDR) An electrical component whose resistance decreases as the light hitting it increases
- Light ray narrow beam of light
- Light year The distance light travels in one year
- Limit of proportionality The point when Hooke's Law is no longer obeyed.
- Liquid One of the three states of matter, along with solid and gas
- Live wire The wire in a plug that carries the current
- Longitudinal wave A wave where the displacement causing the wave is in the same direction as the movement of energy of the wave
- Magnet An object that can attract anything made from iron, steel, nickel or cobalt
- Main sequence The main, stable part of a star life cycle.
- Mains electricity The electricity that is supplied to our homes
- Mains supply The electricity that is supplied to our homes
- Mass The amount of stuff that something is made from
- Medium A general name for a material that a wave is passing through.
- Mega An abbreviation meaning "1,000,000"
- Melting point The temperature at which a solid turns into a liquid
- Metal A substance containing delocalised (free) electrons - they are good conductors of heat and electricity
- Microwaves Part of the electromagnetic spectrum with a wavelength just below radio waves
- Momentum Any moving object that has mass has momentum
- Mutation A random change in DNA
- N A unit to measure force in
- National Grid A system of transformers and cables that sends electricity around the UK
- Nebula A collection of dust and gas. The first stage in the life cycle of a star.
- Neutral wire The blue wire inside a plug
- Neutron A particle found inside the nucleus of an atom
- Neutron star A type of star that comes after the supernova of a red supergiant.
- Newton A unit to measure force in
- Newton's 1st Law An object will stay stationary or move with constant velocity unless an unbalanced force acts on it.
- Newton's 2nd Law An unbalanced force will cause a body to accelerate in proportion to the force.
- Newton's 3rd Law Every action has an equal and opposite reaction force.
- Noise pollution Unwanted noise that can be annoying
- Non-contact force A force that exists between two bodies without them needing to be in contact with each other.
- Non-ohmic Non-ohmic behaviour is when the voltage across a device is not proportional to the current through a device.
- Non-renewable Supplies of a non renewable substance will eventually run out eg fuels like petrol and diesel
- Normal A line at 90 degrees to a surface that is used to help construct ray diagrams.
- North pole A part of a permanent magnet that will be attracted to the Earth's south pole
- North-seeking pole A part of a permanent magnet that will be attracted to the Earth's north pole
- Nuclear fission A type of nuclear reaction that splits a nucleus to release energy
- Nuclear fuels Non-renewable sources of nuclear energy. They are radioactive and used in nuclear fission reactions.
- Nuclear fusion A nuclear reaction that happens in stars when small nucleii (usually hydrogen) are combined to form larger nucleii (i.e. helium)
- Nuclear power station A type of power station that uses nuclear fission reactions to generate electricity.
- Ohm The unit for electrical resistance
- Ohmic Ohmic behaviour is when the voltage across a device is proportional to the current through a device.
- Opaque An object that does not allow light to go through it.