Lesson video

Hello, everyone.

I'm so excited to see you.

My name is Miss Couves.

What's your name? I thought I would start by showing you what I'd been doing during the lockdown.

I have been growing plants in my garden.

I have grown lots of things and that are almost ready to eat.

Look at my chilli plant.

Can you see that they're turning from yellow to red.

When they're red, there'll be ready to eat.

Yum, I'm so excited.

What have you been doing during the lockdown? That sounds like fun too.

Today I'm going to be teaching some science, which is great because science is my favourite subject.

In this unit, we're going to be learning about sustainability and why it's really, really important to protect our planet.

Let's get started.

This is what our lesson looks like today.

We are going to start with a recap of the things we may already know.

Then we are going to learn about the common properties of materials.

Some synthetic materials called glass, ceramic and plastics.

And what happens to those materials when they are thrown away.

In this lesson, you will need an exercise book or paper and a pencil.

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

Natural materials are materials that come from a plant, an animal or the ground.

Tell the screen.

Where did natural materials come from? That's right.

Natural materials come from a plant, an animal or the ground.

Three examples of natural materials are cotton, wool and coal.

cotton comes from a plant.

Wool, comes from an animal.

And coal comes from the ground.

Why is cotton a natural material? Cotton is a natural material because cotton comes from a plant.

Pause the video now and write down three examples of natural materials.

Press play when you're ready to continue.

Synthetic materials are made by humans.

Tell the screen what is a synthetic material? That's right.

A synthetic material was made by humans.

Some of synthetic materials are plastic, glass and ceramics.

Pause the video and write down three examples of synthetic materials.

Now we are going to look at the properties of materials.

We'll use these words to describe the materials later, so make sure you make a note of each definition.

I will tell you when suppose the video and when it's time to write them down.

An opaque object is a material that you cannot see through.

Tell your screen, what does the word opaque mean? Well done.

Opaque means that you can't see through it.

I've written down three examples, an exercise book, a ceramic mug and a plastic box.

Can you think of anymore? Have a look around your house, what can you see? A transparent object is a material that you can see through.

Tell your screen, what does the word transparent mean? Well done.

It means that you can see through it.

I've written down three examples.

Can you think of any more? If your example was something you could see through, your right, that's a transparent material.

Pause the video now and write down the definition of opaque and transparent.

When you're finished, press play to continue.

A material is brittle if it breaks easily.

Tell your screen, what does the word brittle mean? Brittle means that it breaks easily.

I've got three examples of materials that's are brittle glass, a ceramic mug and a plastic box.

Can you think of any more materials that break easily? A material is malleable if it can be bent into shape.

My turn, malleable, your turn? Great pronunciation.

What does the word malleable mean? Malleable means a material can be bent into shape.

I've got three examples, a metal wire, metal sheets, and clay.

Can you think of any more? Pause the video now and write down the definition of brittle and malleable.

If a material has a high melting point, it means it requires a lot of energy to melt.

So it doesn't melt that easily.

Examples include a metal, a ceramic and glass.

How much energy to metals require in order to melt? That's right.

Metals have a high melting point and so they require a lot of energy to melt.

Materials that have a low melting point require a small amounts of energy to melt.

Think about ice.

If you left ice on the table, it would melt.

It doesn't require that much energy to melt because it has a low melting point.

Plastic has a higher melting point than ice.

It requires more energy to melt than ice, but much less energy than a metal or ceramic or glass.

So we say it has a low melting point.

Pause the video now and write down the definition of high melting point and low melting point.

Press play when you're ready to continue.

I'll find a property that we're going to look at is whether something is a good conductor or a poor conductor.

A good conductor is a material that heat passes through easily.

An example of a material that heat passes through easily is metals.

If you have a metal object outside on a hot day, the metal gets hot really, really fast.

That's because metals are good conductors.

What does it mean if an object is a good conductor? An object is a good conductor if it lets heat pass through it easily.

Let's think about poor conductors.

A poor conductor is a material that does not let heat pass through easily.

Examples include plastic, ceramics and glass.

What does it mean if an object is a poor conductor? An object is a poor conductor if it does not let him through parser easily.

Pause the video now and write down the definition of a good conductor and a poor conductor.

On the next slide, I need to mix up the key words and their definitions.

I want you to hide the work that you've just done so that you can test your brain to see how much you remember.

It's okay if you get things wrong.

But the act of trying to remember helps us to remember in the future.

Pause the video now and match the words to their definitions.

Press play when you're ready to continue.

On the next slide, I'm going to show you the answers.

If you've got the answer right, I want you to give yourself a tick.

If you've got it wrong, I want you to correct it.

Remember that correcting our work is really important for helping us to improve.

Pause the video now and check your work.

Make sure you add in any corrections.

Press play when you're ready to continue.

Right, so now we're going to use all of those words that we just learned to describe some new synthetic materials.

What does the word synthetic mean again? Synthetic materials are materials that are man made.

What were the examples and synthetic materials that we have? Plastics, glass and ceramics.

Thank you for reminding me.

A synthetic material is a material that is made by humans.

Sometimes we call them manmade.

We're going to investigate the properties and uses of our synthetic materials.

To do this, we're going to need to have this table in our notes.

Pause the video and draw the table into your notes.

Press play, when you're ready to continue.

Here's some information about glass.

Glass is a synthetic material because it's made by humans.

Find the glass column on your table.

We are going to read the information together, and then I will tell you went to fill in your table.

The first bullet point says glass is a large structure made from Silicon and oxygen particles.

That sounds like a description of glass.

Pause the video and write the description of glass in the correct place on your table.

Next, we're going to look at the properties of glass.

The first property is that glass is transparent.

What does the word transparent mean? Transparent means that you can see through glass.

If I look at my window, I can see through my window.

The second property is that glass is brittle.

What does the word brittle mean? The word brittle means that it breaks easily.

So if dropped my glass on the floor, it would smash into lots of pieces.

It breaks easily.

So it's brittle.

The next property is that it has a high melting point.

What does that mean about the energy required to melt glass? The energy required to melt glass is high.

We need a lot of energy to melt glass.

And the final property is that glass is a poor conductor.

What does that mean about glass? It means that glass doesn't let heat pass through it easily.

Pause the video and write down the four properties in the correct place in your table.

Finally, we've got some uses for glass.

Glass is used to make windows, it's used to make bottles and it's used to make jars.

Can you think of any more examples of glass materials? Write all the examples that you can think of in your table.

The next material we're going to look at is ceramics.

We use ceramics to make building materials like bricks, and we also use it to make pots for cooking.

Ceramics are a large structure made from metal oxide particles.

Pause the video and write the description of ceramics in the correct place in your table.

Next let's look at the properties of ceramics.

Ceramics are opaque.

What does that mean about ceramics? If ceramics are opaque, it means that you can't see through them.

Ceramics are also brittle.

What does that mean if I drop my ceramic pot on the floor? If I drop my ceramic pots on the floor, it would break easily because ceramics are brittle.

Ceramics also have a high melting point, which means they need a lot of energy in order to melt.

Why does this make them good for cooking? Yes, I want to put my ceramic pot in the oven.

The oven has a really high temperature, it wouldn't be very good as a pot if it melted.

So I want my ceramics to have a high melting point so that they're useful for putting things in the oven.

Ceramics are also a poor conductor.

What does that mean about ceramics? It means that it doesn't let heat pass through it easily.

Good for keeping my food nice and tasty warm.

Pause the video and write down the properties and uses of ceramics in the correct place in your table.

Our final synthetic material is plastic.

Find the plastic column on your table.

Plastic is the material that we use most.

We make everything out of plastic.

We make clothes out of plastic.

We make pots out of plastic.

We make bags out of plastic.

We make bottles out of plastics.

We use plastic all the time.

Have a look at your clothes now, if you find the label, see if it says the word polyester.

If your clothes say polyester, that means your clothes are made of a plastic.

Plastics are large structures made up of repeating units.

There are lots of different types of plastics.

Polyester, the one we make our clothes out of is one type of plastic.

The plastic bottles that we make are a different type of plastic.

Pause the video and write the description for plastics in the correct place in your table.

Plastics are malleable.

What does that mean about plastics? Malleable means that you can bend an object easily into shape.

That means we can make our plastic objects in all sorts of different shapes.

That's really useful.

Plastics also have low melting points.

What does that mean about the amount of energy required to melt a plastic? The amount of energy required to melt the plastic is quite low.

They're also poor conductors.

What does that mean about plastics? Because they're poor conductors, they don't let heat through very easily.

Pause the video and write down the properties and uses of plastics in your table.

You should now have a table for all your knowledge on the three different types of synthetic materials.

Let's recap.

What's a synthetic material? A synthetic material is a material that is manmade.

Now we're going to test our knowledge using some questions.

Pause the video and answer these six questions in your notes.

When you're ready to continue, press play.

On the next slide, I'm going to show you the answers.

I want you to correct your answers or tick your answers if they're already correct.

So what happens to be synthetic materials after we're finished with them? Well, let's think.

If you use a plastic bottle for water or a fizzy drink, what do you do with the bottle? He probably throw it away.

When we throw bottles away, they're taken to a landfill site.

A landfill site is a large hole in the ground, which we fill with all of our rubbish.

Look at that landfill site, that doesn't look very nice at all, does it? The problem with synthetic materials is that they take a really long time to break down.

Have a look at the slide.

How long does it take for a plastic bottle to break down? 450 years that is so long.

Think about all the plastic bottles we use.

They're all going to exist for 450 years in the environment.

Look at the slide again.

What are the three main problems with landfill sites? Yes, that's right.

Firstly, they don't look very nice, but they also produce harmful toxins and pollutants that damage the environment.

This is a big problem and scientists are working to make sure that we can protect our planet and therefore the environmental scientists.

In the rest of this unit, we're going to look at what environmental scientists say that we can do to reduce the amount of rubbish that ends up here and think about looking after our planet.

Let's test our knowledge.

Pause the video now and answer these three questions.

Check your answers.

Make sure you tick the answers that are correct and correct the answers that you didn't quite get correct.

That was a great lesson.

We learnt so much about synthetic materials, their properties, and what happens to them.

Make sure you test yourself with a quiz at the end of the lesson.

It helps us to remember when we test ourselves.

I look forward to seeing you again, next time.

Bye.