What is Matter Matter is anything that has

What is Matter?

Matter is… anything that has mass and occupies space

There are three common phases of matter: liquid like water solid like stone gaseous like air

Can you identify three states of matter?

A solid will not take the shape of its container So when you put a ball into a flask it doesn’t fill it up or take the shape of the flask - it stays in the same shape – the shape of a ball.

A liquid takes the shape of a flask but doesn’t expand vertically to fill it completely

Gases expand compress to take the shape of their containers and fill them completely Air will expand to completely fill a room, so we can breath everywhere. If it didn’t we would only be able to breath in certain places in the room where there was air, and we would have to hold our breath in other parts where there wasn’t any air.

Heating a solid usually melts it, converts it to a liquid

Liquids evaporate to gases Boiling water turns into steam.

As a liquid cools it freezes to a solid If it is cold enough rain becomes snow.

As gases are cooled they condense to liquids Power stations release hot steam which is cooled by cooling towers and forms rain clouds which return the water back to earth when it rains.

Gases are very compressible but liquids and solids are not For example you can squash a balloon full of gas with your fingers and change its shape easily, but you cannot squash a solid ball easily.

Some solids are very elastic and extendable (stretchy) For example we can stretch (and bend) a piece of rubber a lot and it comes back to it’s original shape.

But some solids are not elastic and break easily or stay bent and some solids can be formed into specific shapes For example if we bend a pencil too much it breaks, or if we bend a wire too much it stays bent. We can also mold clay and it stays in the shape we form.

Some solids conduct heat very well Metal conducts heat very well but cork doesn’t - which is why the wax melts off of the end where it’s attached to the wire, but not off the end where it’s attached to the cork.

Some solids conduct heat poorly Which is why we put hot drinks into polystyrene cups rather than glass beakers - to keep them warm and prevent us from burning our hands!

Some materials are also good electrical conductors Which is why we make electrical circuits out of metal wire and not strips of wood or rubber bands!

But some materials are not good electrical conductors So if we put cork in the circuit the bulb doesn’t light up. Another bad conductor is plastic which is why we coat electrical wires with plastic - to make them safe to handle!

Some materials are harder than others For example chalk and steel can’t cut glass, but diamond can!

State Changes Freezing is the change of state from a liquid to a solid. Melting is the change of state from a solid to a liquid. Vaporization is the change of state from a liquid to a gas. Condensation is the change of state from a gas to a liquid. Sublimation is the change of state from a solid directly into a gas. Deposition is the change of state from a gas directly into a solid. A plasma is a state of matter much like a gas in that it does not have definite shape or volume. The plasma tends to have an abundance of free electrons, so it behaves very differently than gases. While plasma is very rare on Earth it makes up well over 90% of the matter in the universe. Stars are examples of plasmas.

Summary ü We may not be able to see some types of matter but we can easily see their effects, for example, we see a balloon change shape when we fill it with gas and press on it. ü We have seen that solids, liquids and gases can change into each other if we heat them up or cool them down. These changes are called state changes and are described with words like melt, freeze, evaporate, condense, sublime. ü We have seen that some materials can conduct heat and electricity better than others. ü We have seen that some materials are harder than others, and a harder material can be used to scratch, cut or shape a softer one. ü We have seen that matter has different states and different physical properties.