Lesson video

Hi, everyone.

So nice to see you.

How are you doing today? Great.

I have a feeling I'm excited for this lesson.

I'm looking forward to teaching you.

We've got an exciting lesson today where we're going to find out why we change materials.

Okay? So we've had five lessons already in this unit, and in lesson five, we thought about how we change materials in our raw and synthetic materials lesson.

Today we're going to be thinking about why we change materials.

Okay.

Let's get started.

So, our key question today is, why do we change materials? And you are learning with me, Miss Emms. Our lesson agenda is as follows.

So first things first, we're going to do our star words, and then we're going to do some recap questions.

After that we're going to think about how sand is changed to become glass, and then we're going to hear about a famous materials scientist.

And at the end of the lesson, you will be completing your end of lesson quiz.

You're going to need three things in this lesson.

First thing you'll need is an exercise book or paper, the second thing you'll need is a pencil, and the third thing you'll need, hopefully you've already got that ready, is your brain.

If you need to go and get your exercise book or paper and your pencil, then pause the video now to go and do those things.

Off you go.

All right.

We are ready to begin.

Let's have a look at our star words.

Are you ready? ♪ Star words, star words, star words ♪ Materials, raw materials.

And we learned about raw materials in lesson five.

Okay? Materials found in nature that have not been changed by humans.

Synthetic materials.

Remember that means that they've been made by humans.

Scientist, sand, glass, heating.

Fantastic.

So, a quick recap, can you remember some of the raw materials and some of the synthetic materials that we learned about in lesson five of this unit? I will give you one idea, one example.

So we learned that wood is a raw material, and we learned that a paper is an example of a synthetic material.

Can you think of any others? Think really hard, pause the video, and either you can write them down or you can just think about what they are.

Pause the video and do that now.

Right.

Well done.

So now we're going to have a think about changing raw materials to synthetic materials, and how and why it happens.

So, one of the ways in which a raw material can be changed to become a synthetic material is heating.

And when you apply heat to something, it gets hotter, okay? Another way is by mixing that material with other raw materials.

So let's recap with our actions.

Heating, mixing with other raw materials.

Your turn from the beginning.

Heating, mixing with other raw materials.

And finally, the other way that we're going to look at today is reacting with chemicals.

Okay? Reacting with chemicals.

You've got heating, mixing with other raw materials, and reacting with chemicals.

You're going to remember that.

Can you tell your screen the three examples of how raw materials can be changed to synthetic materials? Pause the video and tell your screen now.

Did you get them? We had heating, mixing with other raw materials, and reacting with chemicals.

Okay? So we're going to focus on one example of a specific raw material that's changed to become a synthetic material.

And we are going to think about sand becoming glass.

So in this example, the raw material is the sand.

The raw material is the? Right.

The sand.

And the synthetic material is the glass.

The synthetic material is the? Amazing.

Don't worry about the water or the plastic or the metal, we're thinking about the glass of this bottle.

So glass, a synthetic material, is made from sand which is a raw material.

Well done.

But how? We're going to learn about how, how the sand become class.

They look very different, don't they? They don't look anything like each other.

They have very different properties.

So how does sand become glass? Wow, let's go through the steps.

So first, we're going to do some actions.

The sand is often mixed with some other raw materials.

So imagine you've got your sand, I want you to mix it with other raw materials.

Okay? First, the sand is mixed with other raw materials.

Next, it's heated to a very high temperature.

So first, it's mixed with some other raw materials, next, it's heated to a very high temperature, and then the temperatures is so hot that sand becomes a liquid.

Okay, let's recap those three steps.

First, can you join me with the actions? First, the sand is often mixed with some other raw materials.

Next, it's heated to a very high temperature.

And when the temperature becomes so hot, the sand becomes a liquid.

No longer solid, it becomes a liquid.

And the liquid can be pushed and knocked into whatever shape is needed.

Okay? It can be pushed and knocked into whatever shape is needed.

And then when the liquid cools down again, it becomes a solid glass object that stays in the required shape.

Okay? And that's how glass is made.

Should we recap so that we really understand those steps? So first the sand is often mixed with some other raw materials.

Next it's heated to a very high temperature.

And the temperature is so hot that the sand becomes a liquid.

And it's often a bit confusing because with sand, you can pour sand, which is often a property that we associate with liquid, but it's made, as we know, tiny little pieces and they are solid.

Okay? But it become so hot that it actually becomes a liquid.

And then the liquid can be pushed and knocked into whatever shape is needed.

So whatever you're going to use the glass for.

And when it cools down, it becomes a solid glass object that stays in the required shape.

For example, the window behind me is made of glass and it's really strong, and it was made to be in this shape.

And that's how glass is made.

Let's see how much of that you can remember.

You don't need to use the language that I use, you can use your own words, but using the images to help you, can you write down the steps for how glass is made? First, next, the temperature, and then it's.

And then what happens afterwards? Okay.

So one, two, three, four, five steps.

Don't worry if you can't remember everything, have a go now writing down your five steps for how glass is made.

Pause the video and on your sheet of paper, you can number them, write down your steps for how glass is made.

Pause and do that now.

Right.

Well done everyone.

Let's recap so that you can tick or fix.

And remember, if you're fixing, that's not a big deal.

Mistakes help our brains to grow, they help us to learn even more things.

So first the sand is.

And you don't need to have said all of this, but mixed with other raw materials.

As long as you've got that it's mixed with other raw materials.

And then it's heated, it becomes really hot.

And then it's so hot that it becomes a liquid.

And then the liquid is pushed and knocked into whatever shape is needed.

And when the liquid glass cools down, it becomes a solid glass object that stays in the required shape.

That's a long sentence.

You didn't need all of that, but the liquid cools down and it becomes a solid glass object.

And it stays in that shape.

And that is how glass is made.

So let's have a think about its properties before and after.

And remember, we had to think about properties in lesson one of this unit.

For example, we learned the property soft and hard.

We know that this cup, for example, is hard.

This jumper that I'm wearing is soft.

We learned the properties, absorbent and waterproof, and we learned the properties so soft and hard, and absorbent and waterproof.

And we learned about properties that are transparent and opaque.

So something that I can see through, for example this glass jug, is transparent.

And something that I can't see through is opaque.

Okay? So we learned about those properties.

Now we're going to be thinking about properties again now, as we look at the sand and the glass.

And I want you to describe that properties.

You don't have to write three words for each, but see what you can think of.

So how could you describe the sand? I will give you one example.

I might write, it can be poured easily.

It can be poured easily.

What other properties could you use to describe this? What other properties does the sand have? And what properties does the glass have as a bottle? Can you pause the video, and you can write sand and two or three properties and glass and two or three properties.

Pause and do that now.

Great.

Let's see what you could have had.

So you may have had other ideas.

These are the some of the ones that I thought of.

So the sand is opaque, you can't see through it.

It's rough.

It doesn't feel smooth, it's rough.

You can pour it.

That's the one I helped you with.

And it's absorbent, isn't it? If you think about sand, it absorbs water from the sea.

And glass, transparent, you can see through it.

I can see my screen.

You can see me.

And this is a water glass, it's in a different shape.

It still has that same property if it's a bottle, transparent, strong, okay? It's also smooth.

The opposite of rough as well, smooth.

It's solid, you can't pour it.

You can pour the water inside it, that's a liquid, but can you pour the glass itself? No.

And it's waterproof.

It doesn't absorb any water, it keeps the water in.

Okay? Or out.

It doesn't absorb the water.

It is waterproof.

If you need to tick or fix any of your properties, I'm going to let you pause now on that screen so that you can do that.

Off you go.

Okay, well done.

Now, I want you to use your knowledge of properties to complete the table below.

So on this side, you've got, what is glass used for? And I've given you some examples.

Windows, glasses to drink from, decorations and jewellery.

These aren't glass, but you might have some decorations and jewellery that are made from glass.

And glasses to help people see better, okay? Glasses to help people see better.

And I want you to think about, and it might be all of them, or it might only be some of them, but out of these properties, so we've got transparent, strong, will stay in the same shape, can be made into lots of shapes and waterproof, which of these are really helpful when it comes to making these windows, glasses to drink from, decorations and jewellery, and glasses to help people see better? For example, let me help you out with one.

Windows need to be transparent so that you can see through them.

You need to be able to see through windows.

So it's good that glass is transparent.

That's a property that it has that makes it a good window.

What other properties does glass have that makes it a good window? Can you have a think? And then can you do the same for glasses that you drink from, decorations and jewellery, and glasses to help people see better, each time looking at your properties here and deciding which ones work best for each purpose? Pause the video now and have a go at filling in this table.

Off you go.

Amazing.

Well done.

So what did you find? You might have not had exactly the same answers as me, but broadly, you may have had a mixture of all of the properties or some of them.

So windows need to be strong, they need to be transparent, and they've got to be waterproof.

Haven't they? Because if it rains, they need to be waterproof.

Glasses to drink from, again they need to be waterproof so that they don't absorb all your water.

It's good that glass can be made into lots of different shapes, okay? Because here it's the same material, but I've got it made into this shape here for my jug, this shape for my water glass, for different kinds of glass, for different kind of drink, it might be made into a different kind of shape.

So it's great that glass can be made into lots of shapes when you're making glasses to drink from.

And it's also great that it's strong.

If it wasn't strong it would break really easily.

Obviously, if I dropped the glass, it would smash, but it's good that it's strong as well.

And decorations and jewellery.

Great that glass can be made into lots of shapes so that you can make lots of shapes of decorations and jewellery.

That's a property that glass has that's really useful when making decorations and jewellery.

And again, strong so that they don't break.

And finally, glasses to help people see better.

If I had glasses that were opaque, I wouldn't be able to see anything.

Would I? So they need to be transparent, strong, and again, made into lots of shapes because you might want to have the glass in your glasses to be in different shapes.

If you need to pause the video here to have a look more carefully at this and tick or fix, then you can do that now.

Now we're going to think about a famous material scientist.

And she was called Stephanie Kwolek.

Stephanie Kwolek.

And Stephanie Kwolek is famous because she invented a material called kevlar.

And this material.

She's an American chemist.

And this material is a material that is five times stronger than steel.

So she used steel and she made a material called kevlar, which is five times stronger.

Okay? So that's an example of how you can invent a material that has better properties, that's even stronger than one that has come before.

Great.

So quickly, what did Stephanie Kwolek invent, and why was this an important invention? Pause the video and tell your screen.

Off you go.

She invented kevlar, and it's important because it was five times stronger than steel.

And it's going to be time now for your end of lesson quiz.

Well done today.

You've done some really, really great learning.

I'm really proud of all of your hard work.

It's time for a special rainbow clap that goes like this.

You ready? Wuaaaaaah.

Your turn.

Great job in all of these six lessons, you've done an amazing job.

If you would like to share your work from this unit, if you've got any pieces of work from this unit of lessons, you'd like to share with Oak National, then you can ask your parents or carer to share your work on Instagram, Facebook, or Twitter, tagging @OakNational with #LearnwithOak.

But do remember that you need to ask your parents or carer to do that for you.

Okay, everyone, great job.

We'll see you next time.