Lesson video

Hi everybody.

My name is Missy Simkin.

I am going to be teaching you science and I absolutely love science.

My favourite thing to learn about in science is animals, especially animals that live under the sea.

Marine animals.

In fact, I love Marine animals so much that I learned quite an unusual hobby.

So my favourite hobby is to go scuba diving, which if you don't already know is when you put on a funny wet suit, you put a tank of air on your back, and then you breathe from the tank of air through something called a regulator that goes in your mouth.

It makes a funny sound like this.

And it means you can breathe underwater.

And I absolutely love doing that.

I've got to see some amazing things, really colourful fish, turtles, rays, and even some small sharks.

So the first thing that we are going to do is, we are going to go through the structure of our lesson.

So this is what we are going to learn today.

We're going to start by learning what rock is.

Then we're going to look at the structure of the earth.

Then we're going to look at how igneous rock is formed.

And I have a demonstration that involves ice and chocolate to show you.

Then we're going to look at intrusive and extrusive igneous rock.

And then lastly, we have an exercise, where we are going to classify different types of igneous rock.

Before we begin, you'll need for this lesson, a pencil, a piece of paper, either just a scrap piece of paper, or if you have a notebook, that would be great.

And you'll need a ruler.

Those are the only thing that you'll need.

But if you don't have those things ready, then please pause the video now and go and get them.

Great.

Once you're ready, we will start with our star words.

So we will start and end every lesson with our star words.

Our star words are the key vocabulary for the lesson.

Sometimes I will explain the star words at the beginning of the lesson, sometimes I will explain them as we're doing our learning in the lesson.

So our star words today are rock, igneous rock, grain, magma, lava, which is hiding behind here this picture of me.

Extrusive and intrusive.

Extrusive and intrusive are two different types of igneous rock.

And we're going to learn why they're different towards the end of the lesson.

A grain is a small, hard particle of something, okay? And the other words, we will learn as we go through the lesson and then we'll come back to them at the end.

So what is rock? So what is rock? We can think of rocks as lots of little grains that fit together.

So you can see in this picture, that zoomed in on a rock, you can see the little grains that are different colours, black and white and grey fitting together.

So that's what we can think of rock as.

Lots of little grains that fit together.

And remember, a grain is a small, hard, solid particle.

Rocks come in lots of different shapes and sizes.

They can be as small as a single grain or as big as a building.

So there's a picture down here, some humongous rocks on the coast.

And then there's a picture here of sand.

Sand is actually really, really, really small rocks where each of them is a single individual grain, okay? Rocks also come in lots of different colours and there are three main types of rock.

The three main types of rock are different because they're made in different ways.

And those three types of rock are igneous rock, metamorphic rock and sedimentary rock.

Today we're just going to learn about igneous rock.

But we will learn about metamorphic rock and sedimentary rocks in our next lessons.

So when you see this symbol in our video, it means we have some texts to read.

Often, this will be recap of learning that we've just done.

But it always helps to hear things more than once.

And it also means that when you answer your questions later, you can come back to this part of the video and you'll have the text there in front of you if you need some help.

So you can either listen to me, read it out, or you can follow along using your finger on your screen.

"We can think of rocks as made of grains that fit together.

Rocks can be hard or soft, as small as a grain or as large as a building.

The grains in a rock can have different colours, shapes, and sizes.

There are three main types of rock that are made in different ways.

These are igneous rock, metamorphic rock and sedimentary rock." When you see this symbol, this means that you need to retrieve some information from the text, okay? Or information that we've just learned and you've just heard.

So to answer these questions, you can use your memory, if you've learned what we've spoken about already, or you can go back to the text on the previous screen.

You need to answer these questions on your piece of paper.

You don't need to write the question out, you just need to write the answer.

So the first question is, "What can we think of rocks as being made of?" and "What other three main types of rock?" You can now pause the video and have a go answering those questions.

When you finish your questions, you can unpause the video, press play, and we'll continue with our lesson.

Great, once you're ready, let's check if your answers were correct.

Let's see how good your memories were.

So what can we think of rocks as being made of? Grains that fit together.

And what were the three main types of rock? Igneous, metamorphic and sedimentary rock.

If you got those answers, correct, then you can give yourself a tick, maybe in a different colour if you have one.

If you made a mistake, that's okay, mistakes are the best way to learn new things.

If you've made a mistake, then all you need to do is just correct your answer and fix it now before we move on.

if you need to pause the video to do that, you can do that now.

The next part of our lesson is the structure of the earth.

So let's recap the structure of the earth.

This is what the earth looks like.

If we were to take a big slice out of it, it's made up of four main layers.

The layer on the very inside is called the inner core.

So that's this one here.

The inner core is the hottest part of the earth and it's made of solid iron and nickel.

The next layer is called the outer core.

So we have the inner on the inside and then the outer on the outside.

The outer core is also made of iron and nickel, except it is liquid.

The next layer is called the mantle.

The mantle is the thickest layer and it's made of something called magma.

Magma was one of our star words.

And Magma is molten rock.

So that's melted liquid rock.

Then the final layer of the earth is called the crust.

So I always remember this one because the crust is what's on the outside of your toast or your bread.

And the crust is also what's on the outside of our earth.

The crust is a solid layer.

That's on the outside.

Sometimes we get gaps in the crust of the earth.

And when we get a gap in the crust of the earth, it means that some of the magma can escape through that gap and it forms volcanoes.

So when magma comes out of the earth onto the surface, we actually call it something else.

We then call it lava, which might be a word that you're familiar with if you've learned about volcanoes before.

Let's read our text about the structure of the earth.

"The earth is made up of different layers.

The inner core is the centre and is the hottest part of the earth.

It is solid and made up of iron and nickel.

The outer core is the layer surrounding the inner core.

It is a liquid layer also made up of iron and nickel.

The mantle is the thickest section of the earth, and it is made up of semi-molten rock called magma." Can you remember what it's called when it comes out of the surface? If you know it, say it to your screen.

It's called lava when it comes out of the surface, magma when it's inside the earth, lava when it comes out.

"The crust is the outer layer of the earth.

The crust is a solid rock layer upon which we live." And remember my sticky way for a remembering crust is like the crust on your toast, it's on the outside.

Let's have a look at our questions.

So these are questions for you to answer on your piece of paper.

You don't need to draw this diagram or that you could, if you want to.

The first question says, "What would be the correct labels to add to the letters on the diagram of the structure of the earth?" So instead of drawing the diagram, all you need to do is to write A, and then add the label that would go there.

B, C, and D.

And then your second question is, "What is the crust made from?" Pause the video and have a go at answering these questions now.

Great, once you finish, let's check our answers.

The correct answers were A, was the inner core.

B was the outer core.

C was the mantle, and D was the crust.

And then for the second question, "What is the crust made out of?" The answer is solid rock.

If you got those correct, well done.

Give yourself a big tick.

If you made a mistake, that's okay, just correct your answer.

And I bet next time you answer the questions, you will get them right.

In the next part of our lesson, we are going to look at how igneous rock is formed.

Here, We have a diagram to help us with this explanation.

So down here, we have magma or molten rock on the inside of the earth.

And you can see that the magma is starting to come up through a crack in the earth's crust, okay? And that is where this volcano has formed.

At this crack in the earth's crust.

Now remember, when magma reaches the earth's surface, we then call it lava, okay? Now this is where igneous rock gets involved.

When lava cools, it turns from a liquid into a solid.

And that's when it becomes igneous rock.

So it starts as magma in the centre of the earth.

It comes up to the surface of the earth through a crack in the crust where it becomes cold lava.

And then as it cools down, it hardens, it solidifies, and it forms igneous rock.

I'm going to show you a demonstration now to make those ideas a little bit clearer.

It's demonstration time.

But before we can start our demonstration, we're going to need some things.

So let me get my science box.

This is my special science box.

It is covered in penguins.

A fun fact about penguins is that when explorers first discovered them, they called them strange geese.

Which always makes me laugh.

A very bad name for penguin.

But I guess they'd never seen anything like them before.

So let's see what's in our demonstration box today.

We have got a metal spoon, a tray, some ice cubes, candle, some matches, and some chocolate.

Let's get started.

I'm going to set up like this so that you can see what I am doing.

I'm going to need one of our ice cubes for this experiment.

So I'm going to place that there.

The next thing that we're going to need to do is we're going to have to melt some chocolate.

So I'm going to light this candle.

And then I'm going to break off a piece of our chocolate.

I'm going to resist the urge to eat it.

I'm going to place it on my metal spoon like this.

And now I'm going hold my metal spoon over my candle.

Now that the flame is giving off heat energy, and my metal spoon is a conductor of heat, so it will get hot and then it will melt my chocolate.

You can see already that my chocolate is beginning to melt.

So when my chocolate is a liquid, it represents my molten magma.

You can see if I turn the sprint towards you, it's really starting to melt.

Good thing I'm it on a tray.

So we're going to give it a couple more seconds until it's all melted.

Until it's all liquid.

I'm now going to demonstrate what happens when my molten magma or lava cools, okay? So you'll see that it's a liquid 'cause it's going to drip from my spoon and it's going to drip onto the ice cube.

As it drips onto the ice cube, it starts to cool, just like magma or lava do when they reach the surface.

They move away from the magma chamber.

So I'm going to give that a few seconds.

And then I'm going to show you.

I can blow my candle out now.

So now we have a look at our ice cube.

You can see that my chocolate has turned back into a solid.

It has solidified.

In fact, these bits have turned into solid chunks.

So that's what happens when molten magma or lava cools and turns to igneous rock.

We can see the process by demonstrating it with chocolate.

It's exactly the same.

Our molten chocolate as it cools turns into solid chocolate.

Let's answer our next questions.

So on your piece of paper, can you please write in full sentences? Question one.

"What did the chocolate represent in the demonstration?" And number two, "How is igneous rock formed?" You can pause the video and have a go at answering those questions now.

Great, when you're ready, we'll check our answers.

So you don't have to have the exact same words as this, but you need to have the same ideas.

So what did chocolate represent in the demonstration? The chocolate represents magma or lava when it's liquid.

So when it's melted.

And igneous rock, when it has cooled and become a solid.

And question two, "How is igneous rock formed?" Igneous rock is formed when magma or lava cools and solidifies.

Great, give yourself a tick if you got those answers.

If you made a mistake, that's okay.

Correct yourself using the answers on the screen now.

Next thing that we're going to look at is intrusive and extrusive rocks.

So these are the two different types of igneous rock.

Would you please to have a look at the rocks on the screen.

What do you notice about both of them? What is the same and what is different? Take a moment to have a think.

If you want, you could even just some ideas down on your piece of paper.

Let's have a chat about some of the differences.

The first thing I notice is that they are different colours.

This rock over here is just one colour.

It's kind of a blacky grey.

And this rock over here has black and white and grey and lots of different colours in it.

I can also see that this rock looks almost like one smooth piece of rock.

Whereas in this rock, I can see all the tiny grains.

They even look like crystals that are all joined together.

Let's have a look at this diagram to explain why.

So when I told you about how igneous rock was made before, I didn't tell you both ways.

I only told you one way to start with.

So we learnt that magma in the mantle comes up through a gap in the earth.

And when it reaches the surface of the earth, we then called it lava.

And it solidifies, it hardens, to form igneous rock.

But that is actually how extrusive igneous rock is made.

We can remember that extrusive igneous rock happens on the outside of the earth because the prefix ex often means out.

So that's why we use it for words like exit.

It means out or outside.

So extrusive rock cools on the outside the surface of the earth.

And the because of that, these rocks cool down really quickly because it's much colder on the outside of the earth than it is on the inside of the earth, okay? So extrusive rock cools on the outside and these rocks cool quickly.

Now because they cool quickly, it means that they have really, really fine, really tiny grains and not very many crystals.

So this was our rock that was an extrusive rock.

And the grains and the crystals were so small that we can't really see them.

Maybe with a microscope or with a magnifying glass.

But in that picture, it's hard for us to see.

Now, intrusive rock is made in a different way.

Intrusive rocks are formed down here in this diagram.

So this is where magma leaves the magma chamber, but it doesn't come up to the surface of the earth.

So it's still inside the structure of the earth.

That's why we call it intrusive.

So remember extrusive is outside, intrusive is inside.

And because this magma is cooling down on the inside of the earth, it cools down much more slowly.

It will still be able to feel some of the heat from this magma chamber.

So it will cool down and it will turn to igneous rock.

It will solidify, but it will do that much more slowly.

Because it does that more slowly, it means that the rocks have much bigger grains and crystals in them like this rock here, okay? So intrusive rocks are formed inside the surface of the earth.

So they cool down more slowly.

And that gives them big grains.

Extrusive rocks cool down on the outside of the earth, which makes them cool down much more quickly, which gives them small grains.

Let's see now if we can put that learning to the test.

There are two types of rock here.

Which ones are intrusive and which ones are extrusive? So have to look at them.

Which one do you think has bigger grains? Remember bigger grains are intrusive.

I remember that because there's an I, in big and there's an I in intrusive.

The correct answer is, this rock here is the intrusive rock because it has bigger grains.

This rock here is the extrusive rock because it has smaller grains.

So let's read our comprehension for this section.

Just trying to find where I can move this video screen so that we can see all of the text.

There we go.

I'll make myself teeny tiny.

Intrusive and extrusive rocks.

"The two main categories of igneous rocks are extrusive and intrusive.

Extrusive rocks are formed on the surface of the earth from larva, which is magma that has emerged from underground.

Intrusive rocks are formed from magma that cools and solidifies within the crust of the planet.

When lava comes out of the volcano and solidifies into extrusive igneous rock, the rock cools very quickly.

Crystals inside solid volcanic rocks are small because they do not have much time to form until the rock cools all the way, which stops the crystal growth.

Intrusive rocks cool slowly without ever reaching the surface.

They have large crystals and are usually visible without a microscope." So we're going to answer questions based on that comprehension.

You're going to answer these on your piece of paper.

Question one is, "How is intrusive rock formed?" Remember in India.

"How is extrusive rock formed?" And then, Complete the gaps in the explanation below." Intrusive rocks have hmm crystals because they cool hmm.

Extrusive rocks have hmm crystals because they cool hmm.

Remember what was my sticky way of remembering which one has big crystals? It's because there is an I in big and there's also an I in? There's your hint.

You can now pause the video and have a go at answering the questions.

Great, when you're ready, we will mark our answers.

So extrusive rocks are formed on the surface of the earth from lava, which is magma that has emerged from underground.

You also could have added in that they form as that lava cools and solidifies.

Intrusive rocks are formed from magma that cools and solidifies within the crust of the planet.

If you don't have the exact wording, but you have the right idea to those questions, then well done.

Give yourself a big tick.

In question three, these were the full sentences.

Intrusive rocks have larger or bigger.

You could have written bigger, crystals because they cool slowly.

And remember, bigger has an I in it, so does intrusive.

Extrusive rocks have smaller crystals because they cool quickly.

So give yourself a tick if you got those right.

If not, that's all right.

Just correct your mistakes before we move on.

So in the next part of the lesson, we are going to classify igneous rocks.

That means we're going to put them into groups based on their characteristics.

So what we're going to need to do is we're going to need to draw this table so that you can record your results.

I'm then going to show you lots of different pictures and you are going to see if you can tell if they are interested or extrusive rocks, and then we'll check at the end and see if you were right.

But before we start, if it was me, I would make myself some notes on my paper so that I can remember when I'm looking at my pictures, some kind of handy hints to help me identify my rocks.

So remember, intrusive rocks have big grains.

So I would write intrusive equals big on my piece of paper.

Which means that extrusive equals small.

So small that you sometimes can't see them.

So I would write on my piece of paper, extrusive equals small.

Once you've done that, please then draw this table into your scrap piece of paper or your notebook.

You will need to use a ruler and a pencil.

We always use a ruler and a pencil when we're drawing scientific tables so that we can be really neat and results can be shared with other people.

So you can pause the video and draw a table like mine now.

Great, once you're ready, we will start our classifying quiz.

So I'm going to show you different types of rock, and the name of the rock is underneath the picture, and you will write that here.

Then you'll write a description for what you can see.

So you might write about the colour, you might write about how the surface looks, if it looks smooth, if it looks rough.

And you might write about how big or how small the grains are.

That will definitely help us to identify the next part of the table, which is whether they are intrusive or extrusive.

For this you can write out the whole word, or you can make yourself a code and you can write I for intrusive and E for extrusive.

So let's begin.

Our first type of rock is called basalt.

Have a look at the rock and make some notes in your table.

If you need to pause the video, then go ahead and do that now.

I'm going to go through all the rock types.

If I'm going too fast, just press pause so you can make your notes and then press play to go on to the next rock.

The next rock is called gabbro.

Do you think it's intrusive or extrusive? I'm going to give you a hint.

One of these rocks is intrusive and one of them is extrusive.

Which do you think is which? Great, let's go on to our next rocks.

Our next two rocks are diorite and dacite.

Again, one of them is extrusive and one of them is intrusive.

Can you identify which one is which? Let's have a look at the next rock.

We just have one rock this time.

There's nothing to compare it to.

This rock is called obsidian.

How would you describe it? Write your descriptions in the box.

And then think to yourself, can you see any grains? Can you see those small, solid particles in it? The next rock is, I'm going to try and say it correctly.

Peridotite.

Peridotite.

I think that's how you say it.

Have a look at the size of the grains.

Are they small? Are they big? Can you see just one colour? Can you see several different colours? And decide what you think this rock is.

Okay, this is our last rock.

Here we have pegmatite.

Look closely and write your notes in your table.

Great, make sure you've got all seven rocks filled into your table.

If you skipped any out, then just go back into the video and fill them in now because we are going to check our answers.

Let's see, did you get the same results as me? Bassalt, I couldn't really see any crystals or grain.

So I thought that was extrusive.

In gabbro I could see large crystals or grains and so I thought that rock was intrusive.

With diorite, again, I could see large crystals and grains and I could see a mix of different colours.

So I thought that rock was intrusive.

Dacite, I thought was extrusive because of its small grains.

Obsidian, that was the black, really shiny smooth one.

And that had no grains and no crystals.

And so I thought that was extrusive.

Peridotite has large crystals and grains.

And again, I could see those mixed colours.

So I thought it was intrusive.

And pegmatite has large crystals and grains as well.

And so I thought that rock was intrusive.

Well done If you got any of those right.

If you got a couple wrong, that's all right.

Just correct your answers.

Well done for having a go.

So that brings us to the end of our first lesson.

Before you go and do your post-lesson quiz, let's just recap our star words from this lesson.

So we can think of a rock as lots of grains that fit together.

Graves are small, hard, solid particles.

Igneous rock is a type of rock that forms when magma or lava cools and solidifies.

Magma is hot molten rock and lava is what we call magma when it comes to the surface of the earth.

Then we learnt that there were two types of rock: extrusive and intrusive rock.

Extrusive igneous rock is formed outside on the surface of the earth and intrusive rock is formed inside the surface of the earth.

Thank you for listening so carefully and working so hard this lesson.

I will see you at the same time next week, and I can't wait.

Have a lovely day, everybody.