Page 156 - York Global Science 6 - Physical Science

Glossary

Acid rain – Rain that has acid from pollution in it.
Air resistance – The force that air exerts on moving objects.

Appliance – An object used for a particular job. Most appliances use electricity.
Atom – The smallest unit of matter in a chemical element.

Attract – To pull something nearer.
Average – A usual or typical amount.

Axle – The bar connected to the centre of a wheel that lets the wheel turn.
Balanced – Equal on both sides.

Balanced diet – Eating different types of food, in the right amounts, so that
your body gets the energy it needs.
Biomass – Dead plant and animal material that can be used as a fuel.

Boiling point – The temperature at which a liquid becomes a gas.
Brownian motion – The movement of particles in a liquid or gas that is caused
by collisions between molecules of that liquid or gas.

Chemical change – A change where new substances are formed. The
particles of the substances are different before and after the change.
Chemical energy – Stored energy that is released during a chemical reaction.

Climate change – A change in the world’s weather, especially temperatures
becoming higher.
Coal – A hard, black material from the ground that can burn.

Coastal – Near or by the sea.
Coil – A length of wire wound round and round to make a series of circles.

Concentration gradient – A change in concentration.
Condensation – When a gas changes to a liquid.

Conduction – When heat goes through a substance.
Conductor – A material that electricity or heat can go through.

Conservation of mass theory – How much matter we have before and after a
change is the same, so the mass stays the same.
Contact force – A force that works when two things are touching each other.

Contract – To get smaller.
Convection – The flow of heat through a liquid or a gas.

Data – Information in number form that can be used to learn about something.
Density – How closely particles are packed together in a material.

Diffusion – When one substance spreads through another substance due to
mixing.
156