Hello and welcome to today's lesson from the Unit Rocks and Soils.

This lesson is called Physical Properties of Rocks: Permeability.

Hello, my name's Mr. Loudin and I can't wait to learn science with you today.

I know if you concentrate and work hard, you are going to be amazing learning superstars.

So let's get started.

By the end of this lesson, you'll be able to compare and group different rocks by testing their permeability.

Before we start the lesson, let's have a look at some of the key words.

Permeability.

Rock.

Permeable.

Impermeable.

What do these words mean? Have a think and speak to a partner.

Let's go through the meanings of the keywords now.

Permeability is the ability of a substance to allow liquids like water to pass through it.

Rock is a solid material that occurs naturally in earth.

If a substance is permeable, it will allow water to pass through it.

If a substance is impermeable, it will not allow water to pass through it.

Today's lesson is split into two parts.

The first part is called permeable rocks.

The second part of the lesson is grouping rocks by permeability.

Let's have a look at the first part now, permeable rocks.

Aisha is interested in the physical properties of different materials.

Do you know what physical properties means? Have a think and speak to a partner.

Physical properties are features which can be observed from the way an object looks or feels or can be measured.

Aisha has observed that the material used to make the roof of her house has been letting water through.

She wonders if this is a physical property of the material.

Aisha says, "I wonder why water has been leaking through the roof of our house? We have to catch the drops in a bucket." And look, there's a picture of the bucket catching drops of water, but her friends have some things to say too.

Izzy says, "When we had some slates blow off our roof in the wind, we had a leak too." And Andeep says, "I think it's something to do with the permeability of materials, but I don't really know what that means." Do you know what permeability means? Speak to a partner.

<v ->The permeability of a material tells us</v> if it allows liquid, such as water, to pass through it.

And look on the board, there's a little diagram.

It shows a pipette dropping some water through a material, and out the other side comes some water passing through the material.

This means that the material was permeable.

Geologists test different rocks for their permeability.

A geologist is someone that studies rocks.

This helps them choose which rocks are useful for different purposes.

Let's check for understanding now.

What is permeability? A, the ability of a material to break, bend or snag.

B, the ability of a material to keep you warm.

C, the ability of a material to allow water to pass through it.

Or D, the ability of a material to be magnetic.

Stop the video and have a think.

What does permeability mean? Let's look at the answer now.

What is permeability? Permeability is the ability of a material to allow water to pass through it.

Did you get it right? Well done, scientists.

Let's look at some different types of rocks now.

There's a rock on the board called sandstone, and sandstone is a special type of rock because it allows water to pass through it.

It's permeable, but not all rocks are permeable.

Here's another rock.

This rock's called marble and it's impermeable.

Now we said permeable means water can pass through the rock.

What do you think impermeable means? Impermeable means that water cannot pass through the rock.

So marble is a rock where water cannot pass through it.

It's impermeable.

Let's check your understanding now.

Which of these statements are correct? A, if a rock is permeable, it will allow water to pass through it.

B, if a rock is permeable, it will not allow water to pass through it.

C, if a rock is impermeable, it will allow water to pass through it.

D, if a rock is impermeable, it will not allow water to pass through it.

Talk to a partner and have a think.

Which of these statements are correct? I'll stop the video now.

Did you get it? Let's have a look at which statements are correct.

There were two statements that were correct.

Statement A is correct.

If a rock is permeable, it will allow water to pass through it.

We saw earlier sandstone was a rock that was permeable.

And look, D's correct too.

If a rock is impermeable, it will not allow water to pass through it.

Can you remember the name of that rock that was impermeable from the slide before? It was marble.

Great work scientists.

Oh, look, here's Aisha again.

Now she's learned about permeable and impermeable rocks, and she's starting to think, well, I wonder, is my roof leaking because the slate on top of my roof is a permeable rock? What do you think? Well, there might be a way we can help her find out.

Can you think of a way we can help Aisha to find out whether slate is a permeable or impermeable rock? Speak to your partner now.

How could we help Aisha find out which rocks are permeable and which rocks are impermeable? Can you remember that little diagram we saw before? Maybe that would help us.

Let's have a look at and see what Aisha's friends think.

They're thinking like geologists and they suggest these ideas.

You could hold rocks under a watering can and see if the ground underneath gets wet.

You could put each rock in a beaker of water and see if it soaks up the water.

You could put each rock on a piece of kitchen towel and drop water on it and see if the towel gets wet.

What do you think? Do you think those are good ideas? Have you got any other ideas that could help Aisha? Speak to a partner and have a think? Let's check your understanding now.

True or false? Geologists are interested in the permeability of rocks.

Is that true or false? I'll stop the video while you think.

Let's have a look.

Geologists are interested in the permeability of rocks.

That's true, and I wonder why it's true.

Let's have a look at the two options.

A, geologists need to know how to group rocks for permeability so they can store them neatly in the cupboard.

Or B, geologists need to know about the permeability of rocks so they can choose the correct rock for a specific job.

Which one do you think is right? Stop the video and have a think.

Let's see why geologists are interested in the permeability of rocks.

It's B.

Geologists need to know about the permeability of rocks so they can choose the correct rock for a specific job.

Did you get it right? Well done, scientists.

Which of these questions could Aisha investigate to find out why her roof is leaking? A, which rocks are hardest? B, which rocks are heaviest? C, which rocks are permanent? D, which rocks are permeable? Stop the video and have a think.

Let's have a look now, which of these questions could Aisha investigate to find out which, why her roof is leaking? D, which rocks are permeable? We've been learning all about permeability today, haven't we? Whether water can go through a rock or not.

Did you get it right? Well done, scientists.

Okay, so we're going to go on to task A now, permeable rocks.

And for this task, you'll need a collection of rocks.

Use one of Aisha's ideas or your own, to test which rocks in your collection are permeable and impermeable.

Record your results and make a note of any other observations.

So here I've got a table, and in my table are the collection of rocks I have.

I've got a sandstone rock, a marble rock, a slate rock, some chalk and some other rock too.

Next to each of the rocks, you need to tick whether your rock is permeable or impermeable.

And you might notice some other things, like how the colour of the rock changes or something else.

Write those observations in the furthest column.

Right, now's the time to do some testing.

So off you go, geologists.

Let's check whether those rocks are permeable or impermeable.

Okay, I hope you had great fun being geologists.

What did you find out? Well, you might have something that looks like this.

I found that sandstone was a permeable rock.

It let the water through, and there was some bubbles when I put the water onto the rock too.

Marble was not permeable rock, it was impermeable.

No water went through that rock and I didn't notice any change at all.

Slate was also an impermeable rock, and there were no changes to the slate when I put water on there.

But chalk was permeable and the water that came out the other end of the chalk was quite cloudy.

I found that some rocks were permeable like sandstone and chalk and others like marble and slate were impermeable.

This would give geologists a great idea about which rocks to use for different jobs.

Well done scientists.

Let's look at the second part of the lesson now.

Grouping rocks by permeability.

Aisha tested slate and other rocks to see whether they were permeable.

She put each rock in a beaker of 100 millilitres of water, and it's really important that she used the same amount of water each time to keep the test fair.

You can see on the left hand side, she put marble into the beaker of water.

Then she put sandstone into the beaker of water.

She put slate into the beaker of water.

She put granite into a beaker of water.

She put chalk in the beaker of water.

And she put limestone in the beaker of water.

And she noticed that some of the rocks were giving off bubbles and the water changed from clear to cloudy.

Can you see on the board which one looks really cloudy? The chalk looks really cloudy, doesn't it? Why do you think each of the rocks behaved differently when it was put into water? Think about those words we used earlier in the lesson, permeable and impermeable.

I wonder whether you can use those in your answer? Stop the video and have a think.

Aisha noticed that with some of the rocks, bubbles were coming out of them when the water was put on top.

The water was passing through the small holes in the rock and pushing the air out of the rock.

So here's a picture of the limestone rock and the sandstone rock.

And although it's quite hard to see, there were bubbles that were coming outta the rocks.

The rocks that produced bubbles were permeable as the water passed through them, but the rocks that didn't produce bubbles were impermeable.

They did not let water pass through them.

Some of the rocks, Aisha observed, turned the water cloudy.

The water was pushing bits of the rock off into the glass, which made the water cloudy, and the rocks that made the water cloudy were permeable as the water passed through them.

There's a picture on the board of chalk in water.

Remember chalk's a permeable rock.

The rocks that didn't make the water cloudy were impermeable as they did not let the water pass through them.

Let's check for understanding now.

Sandstone is a permeable rock.

Use your observations of these permeability tests to decide which other rock is permeable.

So the rock on the left hand side, A is called basalt.

The rock in the middle, B is called chalk.

The rock on the right hand side is called obsidian, C.

Which of those rocks do you think is permeable? Stop the video now and have a think.

Did you get it? Let's have a look at the answers.

Which of these rocks was permeable? We learnt earlier that sometimes permeable rocks when you put water on them, give off bubbles or they might make the water cloudy.

Can you see which rock has made the water cloudy? Chalk has.

So chalk is a permeable rock.

Basalt and obsidian are impermeable rocks.

Now, do you remember ask A before? We tested whether rocks were impermeable or permeable by putting water on them.

Aisha's done the same with her collection of rocks, and she's ticked whether they're permeable or impermeable.

Now she wants to group the permeable rocks together and the impermeable rocks together.

Which rocks are permeable? Which rocks are impermeable? Talk to your partner.

So Aisha sorted the rocks into permeable and impermeable.

And here are her permeable rocks.

Chalk, marble, and limestone.

Hmm, I think one of those is in the wrong place.

Talk to your partner.

Which rock has Aisha put in the wrong place and why? Did you get it? Let's have a look.

She's put the marble in with the permeable rocks.

Well, that's not right.

Aisha's results showed that when she added marble to water, there were no bubbles and the water did not turn cloudy.

That means marble's an impermeable rock.

And I think she might have made a mistake here too.

She's put granite, slate and sandstone together as impermeable rocks.

I think one of those might be in the wrong place.

Which one is it? And why? Speak to a partner.

Did you get it? The sandstone's in the wrong place.

Aisha's results showed that when she added sandstone to water, there were bubbles.

That means sandstone's not an impermeable rock.

It's a permeable rock.

Let's check your understanding now.

Rocks can be compared and grouped by their permeability.

Which of Aisha's friends are correct? Izzy says, "I think that slate and marble are impermeable rocks." Andeep says, "I think that sandstone is a permeable rock." Which one do you agree with? I'm gonna stop the video now while you think.

Let's have a look.

Izzy says, "I think that slate and marble are impermeable rocks." Andeep says, "I think that sandstone is a permeable rock." Which friend is right? They're both right.

Marble and slate are impermeable rocks and sandstone is a permeable rock.

Well done scientists.

Aisha looks at her groups again and she looks at the impermeable rocks.

Her results show that slate is an impermeable rock.

So it does not allow water from the rain to pass through it.

So that must mean there's another reason why water's coming into her house.

I wonder what it could be.

Well, Aisha says she concludes that some slates must have blown off in the wind, and that's why the roof is leaking.

Is that what you thought too? Let's look at task B now.

In task A, you tested rocks to see whether they were permeable or impermeable.

Now what I want you to do is make groups of permeable and impermeable rocks using the results from your tests.

Did your results match Aisha's? Use your results to suggest which other rocks Aisha could use to fix her roof and why they might be good.

Right, so you've got some time now to sort your rocks into permeable and impermeable groups.

Have fun scientists.

Let's have a look at some answers now.

We grouped rocks by their permeability.

You may have grouped your rocks like this.

So in the permeable category, you might have had sandstone, limestone, and chalk.

Remember, those rocks let water through, they're permeable.

We could see bubbles.

And with the chalk, we could see the water turning cloudy.

In the impermeable group, you might have had slate, obsidian, granite, and marble.

Those rocks did not let water through, they're impermeable.

Aisha could also use marble, granite, and obsidian to fix her roof as they're impermeable rocks just like slate.

Sandstone, limestone and chalk would not be good choices for roof tiles because they'd let water through.

Is that what you found too? Well done, scientists.

Let's have a look at what we've learned this lesson.

Geologists test different rocks for permeability.

This tell them which rocks allow liquids such as water to pass through.

Permeable rocks such as sandstone, let water through them and permeable rocks such as slate do not let water through them.

Rocks can be compared and grouped by their permeability.

You've worked so hard today scientists, well done, and you've learned all about permeability and impermeability.

Maybe next time you are on the playground, you might be able to find a rock and test whether it's impermeable or permeable.

Well done, scientists.