Lesson video

Hi, everyone.

So nice to see you, how are you today? Great, it's lovely to see you and I'm really looking forward to teaching you this lesson.

My name is Miss Emms and today, we're going to be learning all about what happens when you heat a solid.

Hopefully before this lesson, you've been able to complete and to watch the video of lesson one, where we learn about the differences between solids, liquids and gases.

If you have, then you are ready for this lesson, all about heating a solid.

Okay, let's see what we're going to be doing today.

So, our key question that we're going to answer in today's lesson is what happens when you heat a solid and you are with me, Miss Emms. So, first things first, we're going to go through our star words and then we're going to look at some recap questions, so questions based on our previous learning.

And then we are going to think about what happens when you heat a solid.

You'll then have a chance to watch me do an investigation and record your observations and then do a little bit of an investigation by yourself.

At the end of the lesson, there'll will be a quiz for you to see what you've been able to remember from the learning in this lesson, okay? So, you're going to need a few things in this lesson, an exercise book or paper, a pencil and your science brain switched on and ready to go.

Give it a little rub.

Amazing.

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

Fantastic, we are ready.

Okay, time for our star words.

Are you ready to repeat? Star words, star words, star words.

Solid, we've already learned.

We learned in lesson one about what a solid object is, okay? So where the particles are packed closely together and we know that a solid holds its shape.

We know that a solid? Great.

Heat.

If we apply heat, it means that something gets hotter, okay? If we apply heat, then you'll find out what that can do to solid objects.

Melting, your turn.

Great job and matter, your turn? Amazing, well done.

And we had to think about the word matter in lesson one.

We learned that everything in the world is made up of matter and everything in the world is made of something called particles, okay? We learned there were three states of matter, solid, liquid and gas, well done.

So, a quick recap now.

What is everything in the world made from? Everything in the world is made from? Tell your screen.

Yeah, everything in the world is made from particles.

And what are the three states of matter? I'll give you one.

Solid, liquid, well done and? Gas, amazing.

As a quick recap, I would like you to draw how the particles should be arranged in each box for solids, liquids and gases.

Pause the video and do that now.

Fantastic.

So you should have had them all packed closely together for solids, a little bit more space for liquids and they can be separated more easily, so more space between them, but still close together.

And gases moving fast around with lots of space between them, okay? Okay, so let's have a think about melting.

I'm going to show you some pictures of things that are able to melt.

There's an ice cream, I wonder if you like ice cream.

I like ice cream.

Can you nod if you like ice cream? I thought so, ice cream.

Ice and ice cubes.

So in all of these three pictures, there is heat being applied and the solid object is melting.

I wonder, can you think of another solid object that is able to melt? Tell your screen.

Great ideas and in each of these cases, there's heat's being applied to the solid object.

This looks like quite a sunny day, so it's hot from the sun.

Again here, you can see that the sun is shining, okay? So the ice is melting because heat is being applied and here, there's heat being applied to the ice cubes and they are going to melt.

So melting means to become liquified by heat.

My turn, your turn, liquified, liquified.

That means to become a liquid.

So if I melt something, it means I'm turning it into a liquid by using heat, okay? So melting means to become liquified by heat.

What does melting mean? Amazing.

Can you think of some examples of when solids melt? Okay, so we've already had to think about ice, what else melts when heat is applied? Tell your screen.

Okay, some great ideas, well done everybody.

So, if we look at why this happens, we can think about what happens to the particles.

The more heat you add, the faster the particles move and the faster the particles move, the more they break apart, okay? So the more heat you add, the faster the particles move, start moving your hands and the more they move, the faster they move, the more they break apart.

And that is how you can change the state of something.

So if you add heat to a solid, it changes its state.

Some solids, not all solids but some solids, if you add heat, they can melt, they can change that state because the particles move faster and break apart.

And again, if you did the same thing to a liquid, you add heat to certain liquids, the particles move faster, break apart and change to the gas.

So, the three states of matter are not set.

You can move from a solid to a liquid and a liquid to a gas.

And today, we're going to think about an example of a solid turning into a liquid when heat is applied.

Okay, so when heat's applied, it changes its state.

It changes its? Amazing.

So when you add heat to a solid, it changes state, it turns into a liquid.

Okay, when you add heat, as we saw with some examples of these things melting we're adding heat, they're changing state from a solid to a? From a solid to a liquid, well done.

So, let's have a look at some examples.

What solids can be melted? Chocolate, yum, yum.

Can you nod if you like chocolate? Chocolate can be melted from a solid to a liquid.

Ice can be melted from a solid to a liquid.

And plastic as well can be melted from a solid to a liquid.

Butter can be melted from a solid to a liquid.

I wonder, perhaps you might have seen in your home heat being applied to butter in a pan and that butter melting and using that to either bake or to cook or to heat other things in your pan.

It can melt into a liquid.

And sometimes you might have left some solid butter outside of your fridge, which keeps things cool.

So heat is being applied to it from the heat of the room and that melts the butter.

That's why it has to stay in the fridge.

Okay, we're going to do an investigation now.

I'm going to do an experiment in which I melt a solid.

You should not try this at home because I'm going to be using a candle, which is really hot and can be dangerous.

So you should watch and you should make observations, but do not do this at home.

So, I'm going to melt a small piece of solid chocolate.

What do you think will happen when I apply heat to the chocolate? Can you tell your screen.

When you apply heat to the chocolate, I think, tell your screen.

Fantastic, did you say that you thought it would melt or become a liquid? Because remember, they mean the same thing.

Melting means to become liquified by heat.

So you think it's going to melt.

I want you to draw the following table.

So you need write prediction, don't worry about the pictures.

Prediction, what happens? So you draw a picture of what you can see and what happens? You describe what you can see with words.

So here you're going to write your prediction in this column.

I think that the chocolate, can you pause the video and draw this table including writing your prediction now please, off you go.

Great and when you see the next part of the video, you are going to draw a picture of what happens when Miss Emms melts the chocolate and what happens describing what you can see here with words.

So here a picture and here you're going to write what happens.

Okay, so let's have a look at what happens when I melt some chocolate.

Okay, so here I've got a candle, which is a source of heat, okay? It's not a very big candle.

It's only producing a little bit of heat.

And on my spoon, which is made of metal, a material that conducts heat really well, I have got a piece of chocolate and this chocolate is a solid piece of chocolate.

So as we've spoken about, this is solid, okay? So it's hard and it's not yet melted.

Now, you might not be able to see this really carefully but what do you think is going to happen if I move this spoon down closer to my source of heat? Tell your screen, I think.

I think the chocolate is going to melt and become a liquid.

Let's see.

So I'm holding it close to the source of heat.

I'm holding it close to the candle, okay? Now at the moment, I know you can't see very much but I'm going to show you in a minute.

So I can already see that the sides of the piece of chocolate are melting, they are becoming a liquid, okay? If I show you the bottom, you can see here on the spoon, that the sides of the chocolate are turning into a liquid because I'm applying heat.

Let's do it for a little bit more time to see what's going to happen as I keep it over the source of heat, okay? I can see now it's melting a little bit more.

More of the solid chocolate is turning into liquid, okay? And soon, if I did this for a really long time, not even too long, if I did this for a little bit longer, I would have a spoonful of delicious melted chocolate.

Yum, yum.

I bring it up to show you again.

You'll be able to see that even more of it now is melted and you can see, look on my finger there, that it's turning to a liquid.

Let's do a little bit more.

Okay.

And slowly the whole piece of solid chocolate is melting into a liquid and you can see that the liquid has different properties to the solid chocolate.

Okay, I could pour this if I want to and I could pour it into a container and it would take the shape of that container.

Now, if I did that for a very long time, if I did that for a little bit longer, and what I would find and this is some different melted chocolate but to show you the difference between the properties.

Here is a piece of a solid chocolate.

So, the solid chocolate is hard, okay? And it's maintaining its shape, isn't it? It's keeping its shape.

I can put it on my hand, I can move it.

I can put it on this hand.

It's maintaining its shape because it's a solid, okay? Now, earlier I melted some chocolate, and just like we've seen with the candles, 'cause I melted it on the stove, so applying heat.

And after it was melted, you can see that its properties changed.

So then I would be to pour the chocolate.

You have a look, I'm pouring it from one cup to another cup.

Let's do that again.

So what was a solid piece of chocolate has turned to a liquid, okay? Okay.

So, what did we notice about the properties of the chocolate before and after? I wonder if you can write down a couple of words that describe the properties of the chocolate before melting it, okay? Soft, hard, is it a solid? Is it a liquid before? What properties did it have before Miss Emms melted the chocolate? And what properties did the chocolate have after melting the chocolate? Can you draw this table now? And can you write some properties of the chocolate before melting and some properties of the chocolate after melting? Off you go.

Well done, everybody, let's see what you found.

So before melting, when it was a solid, the chocolate was hard, strong.

It was a solid, okay? You can also use the word solid as an adjective to describe the chocolate.

It was solid and it could be snapped but not poured.

After melting, the chocolate was smooth.

It was a liquid, it poured easily, it was shiny and it took the shape of its container, didn't it? When I poured it into this mug, it took the shape of that container.

Pause the video now and if you didn't get any of these properties, then you can add them to your table, off you go.

Great, well done, everyone.

Now, can you have a go at melting an ice cube by holding it in your hands? This will apply heat.

Before you do, can you watch me do it, so you know what you need to do, and don't forget to ask permission from your parent or carer to use the ice cube.

Watch me do it first.

So you can see that I've got an ice cube in my hand here.

So it's a solid at the moment, okay? And if I put it in the middle of my hands and apply heat to the ice cube, by moving my hands, already I can start to feel the ice cube melting, okay? And you can see, I keep doing it.

You can see that there's some drips coming off from my solid ice cube and I got liquid in my hands, there you can see it dripping.

So it's gone from a solid ice cube to a liquid.

It's changed state because I am applying heat.

I am melting, which means liquefying by adding heat the ice cube, okay? What did you notice? I noticed that when I did it, we noticed that the ice cube, the solid ice cube, when I applied keeping my hands became a liquid and it started dripping, okay? So you could pour that water.

It went from being a solid ice cube to liquid water.

And now, it's going to be time for your end of lesson quiz when you finish the video.

Amazing job today, you have done an amazing job.

You've tried so hard and you deserve a really big, awesome cheer, ready? One, two, three awesome.

One more time awesome.

Amazing job, everyone.

I'll see you next time, bye.