Hello, everyone, this is Mr. James, and I'm ready to do some more science with you.

So I hope that you are feeling rested, ready, and full of curiosity.

Here goes.

Today's lesson is from the unit rocks and soils, and the title of our lesson is Soil Permeability: Do And Review.

Our lesson outcome is, I can carry out and review an investigation to compare how water moves through different soils.

Now, of course, we're going to need some key words to help us with our learning.

So the first one is this one, permeability.

You can say it after me, permeability.

Measure.

Data.

Evaluate.

Permeability is the ability of a substance to allow gases or liquids, liquids such as water, to go through it, to measure, is to use equipment to find numbers that describe a feature of something like its length, its weight, the size of it or the time that's been taken.

Data is information collected during an investigation.

It may be numbers, symbols, pictures, or text.

To evaluate an investigation is to include an explanation of, and degree of trust, how much you trust the results.

Our outline for our lesson today is to start with this, testing soil permeability, and then we'll move on to the second part, which is called application of soil permeability test.

Lucas carried out a fair test to compare different soils and answer his question and this is his question, "Which type of soil is the most permeable?" Explain to a partner what permeable means.

You might like to pause the video now.

Water and other liquids can move easily through a permeable soil, but they move slowly through soils that have got low permeability.

Lucas collected three different soil samples from three different places, his nan's garden, the local park, and the countryside.

And you can see the three samples in the pictures here, sample A, B, and C.

He'd made a plan so that he knew what equipment to use and what to do to make sure that it was a fair test investigation.

Do you know what this means? Pause the video now and have a chat with somebody and see if you can agree what is meant by a fair test investigation.

So this is how Lucas kept his test fair.

"The only variable I changed was the type of soil.

I needed to keep all other variables the same, so I added 120 millilitres of cold water each time and used the same amount of soil." What equipment will Lucas need to measure how much water passes through different soils? Again, have a think about this.

Pause the video and talk to a partner.

So what property of soil can we test by pouring water onto it? Is it A, the flexibility of soil, B, the permeability of soil, or C, the transparency of soil? What do you think? Yeah, it's the permeability of soil that we test by pouring water onto it.

Lucas set up his equipment like this.

Here we see a filter paper inside a funnel and a cup of soil is added to the filter paper.

The funnel is held inside the neck of a bottle and Lucas slowly pours 120 millilitres of water onto the soil.

He times five minutes using a stopwatch, and then he measures how much water has passed through the soil into the plastic bottle by pouring this water into a measuring jug.

Lucas says, "I will repeat my test for the other two types of soil." I'll collect data to show me how permeable each type of soil is, so I can compare them for their permeability.

Let's move on to try a true or false.

When scientists carry out a fair test to investigate soil permeability, they only change one variable.

True or false? Yeah, it's true.

Now though, I'd like you to think why it's true.

I'd like you to justify your answer.

Here are a couple of options.

A, it makes it easier and quicker for them to do a fair test if they only change one variable.

B, they only change the variable they are asking the question about in a fair test.

Which of those do you think is the best answer to why scientists carry out a fair test changing only one variable? Hmm, yes, they only change the variable they are asking the question about in a fair test.

What will Lucas measure to tell him about the permeability of different soils? Will he measure the amount of soil in each sample, the type of soil he used in each sample, the amount of water that passed through each soil sample, or the time it took for the water to pass through the soil samples? Have a think about this.

Pause the video now.

What did you think? Yes, it was the amount of water that passed through each soil sample.

That's what Lucas needed to measure.

So for task A, it's time for you to carry out your own fair test to find out which type of soil is most permeable.

You can use your own plan or you can follow Lucas's ideas for what to do.

Be sure to record your data in a table.

And here's an example of one.

You can see we have the soil samples, A, B, and C, and the space for you to record the amount of water that passed through the soil in millilitres.

Ready to go? Fantastic.

Pause the video now and get yourself set up, ready to conduct your own experiment.

Well done, I hope you found that was an interesting thing to do.

Now then let's have a look at Lucas's results.

Here's his table.

Are your results similar or different? So on soil sample A, the amount of water that passed through the soil was 100 millilitres.

For sample B, it was 80 millilitres, and for sample C, it was 110 millilitres.

Just give you a moment to compare your results.

You can pause the video to do that.

I wonder what your results look like.

Were they similar or were they different? There may be reasons that you can find for those differences when you are comparing them.

Next, we come to the application of a soil permeability test.

So Lucas measured how much water passed through his soil samples in five minutes.

And here in this table is the data that he collected.

From Nan's garden, 100 millilitres after five minutes, from the local park, there was 80 millimetres, millilitres after five minutes.

Important to get that right millilitres, not millimetres.

And from the countryside walk, there was 110 millilitres after five minutes.

What unit did Lucas use to measure the water that passed through the soil samples? Just take a moment to think about that.

Pause the video if you need to.

Did you remember? Yes.

Millilitres, ml as it's recorded here.

Millilitres.

That's the unit that Lucas chose to use to measure the water that passed through the soil samples.

Scientists often evaluate investigations they've carried out to see if they can improve them.

This is what Lucas thought about his investigation.

"When I poured the water onto the soil in the funnel, some of the soil washed over the side.

I also found it tricky to measure the amount of water in the bottle.

I wonder how I could improve my investigation." Can you think of some improvements Lucas could make to his soil permeability investigation? Pause the video and have a talk about that now.

Sophia says, "To improve his test, Lucas could pour the water more slowly." Andeep suggests, "Lucas could add another piece of filter paper on top of the soil to stop the soil falling out of the funnel or add less soil." Laura, her thought is this, "To make it easier to measure, Lucas could put the funnel into a measuring cylinder instead of a plastic bottle." What do you think about these ideas? You can pause the video if you want to talk about them.

Now, for true or false.

Scientists don't need to evaluate their investigations as they already have the correct answer.

True or false? What do you think? Yeah, it's false, but I'd like you to justify your answer.

So let's have a look at a couple of explanations.

Which one do you think is the most correct? Scientists often evaluate their investigations to show how hard they've worked.

That's A.

Or B, scientists often evaluate their investigations to suggest improvements.

What do you think? Yeah, they often evaluate their investigations to suggest improvements.

Look at Lucas's data.

Which soil was the most permeable? You can pause the video to do that.

Yes.

The countryside walk.

That was the most permeable soil and there was 110 millilitres of water produced from the countryside walk soil.

So which soil had the lowest permeability? That's right, the soil from the local park, which produced 80 millilitres after the five minutes that Lucas waited.

Water moves very easily through permeable soils and very slowly through soils with low permeability.

Which of these explain how water moves through permeable soils? A, permeable soils hold water for a long time.

B, permeable soils do not allow water to pass through quickly.

C, permeable soils allow water to pass through quickly.

What do you think? Pause the video if you need to.

Yeah, permeable soils allow water to pass through quickly.

Does your data look similar to Lucas's results? Which of your soil samples did the water flow most quickly through? And which of your soil samples did the water flow most slowly through? You might want to pause the video for a moment to talk about that.

This is what Lucas had to say.

"After evaluating my data, the soil from my countryside walk was the most permeable.

I think this is because it has the largest particles, so water can pass through the spaces in the spaces between." Do you agree with Lucas and why? Pause the video to talk about that now.

Lucas knows that soils with larger particles, like sandy soils, allow water to pass through them more easily and have high permeability.

He also knows that soil with smaller particles, like clay soils, tend to lump together and slow down the water.

These type of soils have low permeability.

Using Lucas's data, which soil do you think had the most sand particles in it? Nan's garden, the local park or the countryside walk? You can pause the video if you need to.

Yeah.

The countryside walk.

Which soil do you think had the most clay particles in it? Again, if you need to pause, pause the video.

Yeah.

The soil from the local park.

Which of these soils has the smallest particles, the silty soil, the sandy soil or the clay soil? Time for you to decide.

The clay soil has the smallest particles.

Smaller particles stick together in larger lumps.

Lucas thinks, "I wonder how soil scientists use their data to help them decide which is the best soil to use for different purposes?" How do you think data about soil permeability helps scientists? Have a chat about that now.

Pause the video.

This village is prone to flooding because the river flows over the riverbank.

It makes life difficult for the people who live there.

The riverbank is made from clay soil with low permeability.

This stops the river water draining away quickly.

The water floods into the village and makes lots of mud.

How could scientists use their soil data to help the villagers? Have a little think about that and pause the video now.

Scientists could add permeable sandy soil to the riverbank and this would increase its permeability.

And you can see that shown in the diagram here.

Here's the sandy permeable soil added to the riverbank.

The river water moves through the sandy soil instead of flooding over the riverbank.

And when the river floods, the sandy soil would allow water to move through it easily.

And this in turn decreases the risk of flooding to the village.

Which of these examples may have been caused by soil with low permeability? Is it A, a drought, B, a road covered in rainwater, or C, flooded houses? Can you see the cars there in the flood water? What do you think? Yes, it's the second of the three, the second two of the three, the road covered in rainwater and the flooded houses.

In places where there's little rainfall, the land often dries up quickly.

Farmers can't grow crops because the soil is too dry.

This farmer's field is made from sandy permeable soil.

When it rains, the water flows through the soil too quickly.

It makes it difficult for plants to have enough water to grow.

How could scientists use this soil data to help the farmer? Have a think about that now.

What ideas have you got? Pause the video now.

Scientists would advise the farmer to mix some soil with low permeability, like clay soils, to their fields.

The farmer would mix the soil with a low permeability into his sandy soil, and when it rains, the soil would hold the water for longer so that the plants could grow and stay healthy.

Here we see a lovely crop of lettuces.

So why is it important for scientists to investigate soil permeability? Here are your options.

A, because it gives them something to do, B, because it can prevent flooding, or C, because it can help plants to have enough water to grow? Decide on your answer.

Pause the video if you need to.

Ready with your answers? Yes.

Here goes.

Well, it is important for scientists to investigate soil permeability, and here are a couple of the reasons why.

Well, it can prevent flooding and it can help plants to have enough water to grow.

Those are two really good reasons for scientists to do their important work.

Andeep thinks about this.

"So understanding soil permeability is really useful." Lucas, "I'd like to be a soil scientist when I grow up so I can help prevent floods and help farmers grow more crops." Scientists evaluate their permeability investigations to help improve people's lives.

Task B, evaluate your own soil permeability investigation.

Which soil was the most permeable? And which had the lowest permeability? What improvements could you make to your fair test investigation and why? And give an example, finally, of how your data could help you to decide which soil would be best to reduce areas of flooding, too much water in soil, or drought, not enough water in the soil.

Time to pause the video and evaluate.

Excellent work.

You may have suggested something like this.

Soil sample A was the most permeable, as the most water passed through it after five minutes.

Soil sample C had low permeability as I measured the lowest amount of water after five minutes.

I would use a larger funnel to make room for all the soil, and I would try to use a wider variety of soil samples to increase the amount of data I had.

I would use sample A soil for the local hockey pitch to stop it getting muddy in autumn, as it has high permeability.

Time to think about all that we've learned.

Scientists investigate how water moves through soils to find out about their permeability.

Scientists will evaluate a completed investigation and suggest improvements.

The size of particles in a soil affect its permeability.

Soils with low permeability may be more likely to flood.

Well, that was a good lot of learning that you did today.

Excellent work.

Well done.

See you next time.

Bye.