Particle theory Aims: 1. To know the three states of matter 2. To be able to relate the particle theory to changes of state 3. To know the terms used to define each change of state

Matter is made up of anything that takes up space and has mass. Does air take up space? Does air have mass?

There are three states of matter. Solids Liquids Gases

Particle Theory All matter is made of tiny particles Particles are called molecules or atoms The particles are attracted to each other The particles are always in motion The amount of motion of particles depends on the amount of (heat) energy

The Three States of Matter Matter can be in one of three “states”. The three states of matter are SOLIDS, LIQUIDS and GASES. What are their properties? Solid Liquid Gas Very difficult to squash, can’t be poured Difficult to squash, can be poured Easy to squash, can be poured

Solids Have a definite shape Have a definite volume Particles are packed tightly together Particles cannot move freely

Liquids Have no fixed shape Have a definite volume Particles are packed loosely together Particles can move a little

Gases Have no definite shape Have no definite volume `Particles are far apart Particles move freely

Activity: Copy out the three states of matter leaving a gap beneath each. GAS SOLID LIQUID

Words to use – strong, close, vibrate, fixed Particle theory Particle theory is all about explaining the properties of solids, liquids and gases by looking at what the particles do. SOLIDS In a solid the particles ______ around a _____ position. There is a ______ force of attraction between each particle and they are very _____ together vibrate fixed strong close Words to use – strong, close, vibrate, fixed

Words – fixed, collide, any, quickly, close, very, solids LIQUIDS In a liquid the particles are _____ together but can move in ____ direction. They won’t keep a _____ shape like _____ do. close any fixed solids GASES In a gas the particles are far apart and move _____ in all directions. They often ______ with each other and because they are far apart they can be easily _______. quickly collide squashed Words – fixed, collide, any, quickly, close, very, solids

Changes of State Liquid Solid Gas melting evaporating freezing condensing

Changes of State Changes of state occur when one state of matter (i.e. solid, liquid or gas) is changed into another… 2) If even more energy is supplied to the liquid the bonds will be completely broken and the liquid will turn into a… 1) If enough energy is supplied to a solid the particles will break free from their fixed positions and the solid will become a… GAS LIQUID 3) A gas can be turned straight back into a solid, but this is very rare

Changes of State What are these processes called? Choose from freezing, boiling, melting, condensing Boiling Melting Freezing Condensing

Some definitions… Melting A change of state – solid to liquid A change of state – liquid to gas A change of state – gas to liquid A change of state – liquid to solid Evaporation Condensing Freezing

Quiz Solid, liquid and gas Name the 3 states of matter Which of the 3 states can’t be poured? Which of the 3 states is water vapour? Which of the 3 states will match the shape of any container? Which of the 3 states is most easily compressed? What is the name of the change of state for when a liquid turns into a gas? What is the name for when a gas turns back into a liquid? Solid gas Gas & liquid gas boiling Condensation

Activity: Pretending to be particles Thunderbolt kids