L1 - Solids, Liquids & Gases

objectives

• State the distinguishing properties of solids, liquids and gases.
• Recalled (Yr7) Particle theory

Explaining States of Matter

• So why are some things solids and others liquids and gases?
• What makes a solid different to a liquid or a gas?

It is all to do with PARTICLES

All substances are made up of tiny pieces called PARTICLES. These are arranged differently in solids, liquids and gases

What do the particles in solids liquids and gases look like?

•Solids, liquids and gases are the three states of matter

•Their particles are arranged differently, giving them their special properties…

•Do you know how these particles are arranged?

Solids

•The particles are very close together

•The particles are arranged in a regular pattern

•The particles cannot move from place to place, but the particles can vibrate in a fixed position

•Solids are held together by strong forces called bonds

•Solids have a fixed shape, e.g. wood, plastic, steel, ice (solid water)

Why do solids have a fixed shape?

• Solids have a fixed shape because the particles can’t move from place to place

Do you think you could compress (squash) a solid?

• Solids cannot be compressed because the particles are very close together, and have no space to move into

Liquids

•The particles are close together

•The particles are arranged in a random way

•The particles can move around each other - the bonds in a liquid are strong enough to keep the particles together, but weak enough to let them move around

•Liquids flow, and can change shape, e.g. water, lemonade, mercury, (all liquids at room temp.)

Why can liquids change shape?

• Liquids can change shape because the particles can move around each other

Do you think you could compress (squash) a liquid?

• Liquids cannot be compressed because the particles are close together, and have no space to move into

Gases

•The particles are far apart

•The particles are arranged in a random way

•The particles can move quickly, in all directions - there are no bonds between the particles in a gas

•Gases flow, and completely fill their container, e.g. air, helium, chlorine (gas at room temp.)

Why do gases have no fixed shape?

• Gases can move quickly in all directions, filling their container

Do you think you could compress (squash) a gas?

• Gases can be compressed because the particles are far apart, and have space to move into

Properties of the States of Matter

Compression (Squashing)

•Look at the demonstration of compression in a solid, liquid and gas

•Which of the syringes will we be able to compress, the syringe with the sand in, the water in, or the air in?

•Why do you think some will compress, and other will not?

•Why is it the gas would compress, but the solid and liquid did not?

•Draw out this experiment, labeling the three syringes with the solid, liquid and gas in, and using your scientific knowledge of particles explain why only the gas compressed