KS3
States of Matter
States of matter is the science around how particles act when in different states. Below you will find out about solids, liquids and gases.
Particles
A particle is the amount of matter that is used by scientists to design theories about their field of study.
Particles consist mainly of atoms, ions or molecules. Particles make up most things.
There are three states of matter, these are solids, liquids and gases. We use the particle model to represent how the behaviour of these states is different.
Solid state
The particles in a solid are touching each other and are organised. Forces of attraction hold them together.
The particles vibrate around a fixed position, so cannot flow.
Solids have low amounts of kinetic energy.
Cannot be compressed.
Liquid state
The particles in a liquid have more kinetic energy than a solid. Particles are touching each other but in an unorganised way.
Forces of attraction are weaker than a solid and so particles can break free.
The particles are able to move around each other. Liquids are a type of fluid because they can flow.
Cannot be compressed.
Gas state
The particles in a gas are spaced out and unorganised. Particles are able to move in any direction. Gases are a type of fluid as they can flow.
There are little to no forces of attraction.
Gas particles have the highest level of kinetic energy.
Can be compressed due to space between particles.
Changing states
Melting
When a solid gains enough energy it changes into its liquid state. We call this its melting point.
Boiling | Evaporation
When a liquid gains enough energy it changes into its gaseous state. We call this its boiling point. A liquid can also become a gas through evaporation. This is a slower process where the liquid never reaches its boiling point.
Endo sounds similar to enter
When substances take in energy from their surroundings we refer to this as an Endothermic reaction.
Condensing
When a gas condenses it releases energy (normally by cooling) into its surroundings becoming a liquid.
Freezing | Solidification
When a liquid freezes it releases energy into its surroundings causing the liquid to become solid.
Exo sounds similar to exit
When substances release energy into their surroundings we refer to this as an Exothermic reaction.
Gas pressure
When gas particles collide with the walls of their container they apply a force, we call this force gas pressure. This force (pressure) is applied to a specific area for example the inside of a balloon.
Increasing pressure
When a balloon is empty it has the same amount of air particles on the inside as it does on the outside. When you inflate the balloon you put more particles in the balloon. This means more particles collide with the inside of the balloon increasing pressure.
How temperature effects pressure
When temperature increases the gas particles gain more energy. This means the higher the temperature the higher the pressure. This is because the particles move faster and collide more with other particles and the container.
How volume effects pressure
When we decrease the volume of a container, we increase the pressure. This is because the particles collide with the walls of the container more.
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