Lesson video

Hello there, my name is Miss Couves.

What's your name? I'm so excited to see you today.

We are going to begin a brand new unit on chemical and physical changes.

Today, we're going to learn about how particles behave in solids, liquids, and gases, and what happens when we heat substances up and cool them down.

Are you ready? Today we will restart by recapping our previous knowledge.

Then we will look at the properties of solids, liquids, and gases.

We'll find out what happens to substances when they are heated or cooled, and what these changes of state are called.

For this lesson, you will need a piece of paper or an exercise book and a pencil.

If you don't have one of these items, pause the video now and go and get it.

Let's start by recapping our previous knowledge.

Can you remember which state of matter each diagram represents? The first diagram shows the particles touching in ordered rows.

Which state of matter does the diagram represent? This diagram represents a solid.

In solids, the particles are touching and arranged in ordered rows.

The second diagram has particles that are touching but arranged randomly.

Which state of matter does this diagram represent? This diagram represents a liquid.

The particles in a liquid are touching but not arranged in ordered rows.

The final diagram shows particles that are not touching and moving very fast.

Which state of matter does this diagram represent? This diagram represents a gas.

The particles in a gas do not touch and move quickly in all directions.

We use separating techniques to separate mixtures into pure substances.

When do we use filtration? We use filtration to separate an insoluble solid from a liquid.

When do we use sieving? We use sieving to separate an insoluble solid from a liquid when the solid is large enough not to fit through the holes in the sieve.

When do we use evaporation? We use evaporation to separate a soluble solid from a liquid because the liquid has a much lower boiling point than the soluble solid.

Let's think about the properties of solids, liquids, and gases.

We are going to start by thinking about the arrangements of particles in solids, liquids, and gases, and how the particles behave.

Pause the video and copy this table into your notes.

When you're ready to continue, press play.

The particles in a solid are close together.

They are touching.

The particles are arranged in ordered rows, and the particles are vibrating on the spot.

Pause the video to complete the first row of your table.

Press play when you're ready to continue.

Particles in a liquid are also close together.

They are also touching.

The particles are arranged randomly, and the particles are able to slide past each other.

Pause the video to complete row two of your table.

Press play when you're ready to continue.

The particles in a gas are far apart.

They are arranged randomly and moving in all directions.

The particles move fast in all directions.

Pause the video to complete the final row of your table.

Press play when you're ready to check your answers.

Pause the video to tick and fix your answers.

Pause the video and write a sentence to describe the particles in a liquid.

Pres play when you're ready to continue.

The particles in a liquid are touching and arranged randomly.

They are moving and able to slide past each other.

Now we're going to look at the properties of solids, liquids, and gases.

Solids cannot be compressed because there is no space between the particles.

They do not flow because the particles cannot move past each other.

And they have a fixed shape because the particles cannot move past each other.

Three properties of solids are that they cannot be compressed, they do not flow, and they have a fixed shape.

Pause the video and write down three properties of solids.

Press play when you're ready to continue.

Three properties of solids are that they cannot be compressed, they cannot flow, and they cannot change their shape.

Let's look at the properties of liquids.

Liquids cannot be compressed because there is no space between the particles.

Liquids can flow because the particles can slide past each other.

And liquids can take the shape of the bottom of the container because the particles can slide past each other.

The three properties in liquids are that they cannot be compressed, they can flow, and they can take the shape of the bottom of their container.

Pause the video and write down three properties of liquids.

Press play when you're ready to continue.

Let's look at the properties of gases.

Gases can be compressed because there is space between the particles.

They can flow because the particles are moving all of the time in all directions.

And they can fill the shape of their container because the particles are moving all of the time in all directions.

Three properties of gases are that they can be compressed, they can flow, and they can fill the shape of their container.

Pause the video and write down three properties of gases.

Press play when you're ready to continue.

Now we're going to look at what happens when we heat or cool particles.

Particles in a solid are vibrating on the spot.

In a liquid, they're sliding past each other.

And in a gas, they're moving fast in all directions.

As a substance is heated, the temperature increases.

When the temperature increases, the particles have more energy and will move around more.

What happens to the particles when they are heated? When particles are heated, they have more energy.

Pause the video and write down what happens when particles are heated.

Press play when you're ready to continue.

When particles are heated, their particles gain energy and move around more.

Pause the video and complete this diagram in your notes.

Press play when you're ready to continue.

Pause the video to tick or fix your answer.

Check that your diagrams match the diagrams on this slide and that you identified that as the temperature increases, particles have more energy.

When substances are cooled, the particles have less energy.

This means that they move around less.

Now we're going to think about changes of state.

A change of state happens when something change from one state of matter to another.

When a solid becomes a liquid, it is called melting.

My turn, melting.

Your turn.

Which change of state is called melting? Melting is when a solid changes to a liquid.

When a liquid becomes a gas, it is called boiling.

My turn, boiling.

Your turn.

What is boiling? Boiling is when a liquid becomes a gas.

When a gas becomes a liquid, it's called condensing.

My turn, condensing.

Your turn.

Which state change is involved in condensing? Condensing is when a gas becomes a liquid.

When a liquid becomes a solid, it is called freezing.

My turn, freezing.

Your turn.

Which change of state is called freezing? Freezing is the change of state from a liquid to a solid.

Pause the video and complete the diagram in your notes.

Press play when you're ready to check your answers.

Pause the video to tick and fix your answers.

Press play when you're ready to check your knowledge.

Which state changes involve particles gaining energy? Option one, melting.

Option two, boiling.

Option three, condensation.

Option four, freezing.

What do you think? State changes that involve particles gaining energy are melting and boiling.

Which state changes involve particles losing energy? Option one, melting.

Option two, boiling.

Option three, condensation.

Or option four, freezing.

What do you think? The state changes that involve particles losing energy are condensing and freezing.

Pause the video and complete the table to identify the state change and how you knew.

For example, for the first question, when steam is produced from a kettle, a liquid is turning into a gas.

Which state change is that? This is evaporation or boiling.

How did I know that? I know that it was boiling because a liquid turned into a gas.

Pause the video to complete the table.

Press play when you're ready to check your answers.

Pause the video to tick or fix your answers.

Steam produced from a kettle is boiling because liquid water is becoming a gas.

Rain turning into snow is freezing because liquid water is becoming a solid.

An ice cream on a hot day melts because the solid ice cream is becoming a liquid.

And water forming on the bathroom mirror is condensing because steam is becoming a liquid.

Well done for all your hard work today.

You've learned so much about the changes of state.

Make sure that you do your quiz so that you can recap your knowledge.

See you next time, bye!.