In a _?_, we cannot see the different substances because they are combined more evenly.

Which method of separation would you use to separate a mixture of iron and plastic?

Which method of separation would you use to separate a mixture of dust and air?

Which method of separation would you use to separate a mixture of petrol and water?

Which method of separation would you use to separate a mixture of sand and water? (2 possibilities)

Which method of separation would you use to separate a mixture of sugar and water?

Which method of separation would you use to separate a mixture of ethanol and water?

Which method of separation would you use to separate a mixture of salt and water?

Which method of separation would you use to separate a mixture of metal and rubbish?

Bread is a _?_ .

Carbon dioxide is a _?_ .

Cheese is a _?_ .

A flame is a _?_ .

Juice is a _?_ .

Milk is a _?_ .

Nitrogen is a _?_ .

Rain is a _?_ .

Sand is a _?_ .

Smoke is a _?_ .

Snow is a _?_ .

Tea is a _?_ .

_?_ is the amount of matter in an object.

_?_ is the width times the height.

_?_ is the amount of space that an object occupies.

_?_ is temporary and can be reversed.

_?_ is the amount of matter that occupies a space.

_?_ is permanent and cannot be reversed.

A chemical reaction caused by microscopic organisms when the break down organic materials.

A chemical reaction that occurs when oxygen in the air reacts with a fuel.

A chemical reaction that occurs when some metals and foods react with oxygen in the air.

A chemical reaction that produces energy in the form of heat and light.

A chemical reaction used to make many foods.

A chemical reaction that produces waste products.

It comes from a source that produces vibrations.

It is released during a chemical reaction.

It is energy stored in objects.

Most of it comes from the Sun.

It comes from motion.

The sum of the potential and kinetic energy in an object.

It takes the form of heat.

It can be converted into light, heat, sound and movement.

Light is the _?_ form of energy in the Universe.

Light passes easily through materials that are _?_ .

When light passes from air into water, it is _?_ .

We can use _?_ to refract light.

Refraction happens when light changes _?_ .

It is a curved piece of transparent glass or plastic.

Lenses have two main shapes that _?_ light in different ways.

_?_ lenses or negative lenses bend light outwards over a larger area.

_?_ lenses or positive lenses bend light inwards and focus it on a smaller area.

We have _?_ lenses in our eyes.

We use _?_ lenses in projectors and lighthouses.

The Sun, the stars, lightning, fire and some bioluminescent animals are examples of _?_ .

Lamps, light bulbs and torches or flashlights are examples of _?_ .

It is the fastest form of energy in the Universe. It travels at a speed of 300,000 kilometers per second.

White light is actually composed of _?_ colours. These are the colours we can see in a rainbow.

Light travels in a straight line.

Some materials can absorb light and other materials can reflect light in a new direction.

The temperature of an object depends on how much _?_ energy its particles have.

When the air in a room becomes warmer, the particles _?_ .

When a hot metal comes into contact with a cold metal, the heat is transferred by _?_ .

When all the particles of an object have the same energy, there is _?_ .

When a particle heats up, its particles move in a circular motion called _?_ .

Cookers and home heaters produce heat energy in the form of _?_

Dense materials, such as metals are good _?_ because they transfer heat easily.

_?_ can be transferred over a distance without any physical contact

When we heat an object, we add _?_ .

Thermal _?_ are materials that conduct heat very well. Some excellent examples are copper and aluminum.

Thermal _?_ do not conduct or transfer heat very well. Some excellent examples are wood, plastic and wool.