Lesson video

Hi everyone, my name is Miss Dhillon and the question we are going to be exploring in today's lesson is where is Earth's water? Don't you just love a fresh glass of water? We use water everyday.

So it's really important for us to understand and know where it comes from.

Let's start by looking at the structure of today's lesson.

This is what it's going to look like.

We're going to start with the star words.

Then we're going to think about the question, where is Earth's water? We're going to then look at states of matter, looking at real life examples and finally, finishing with the water cycle.

For this lesson, you will need a piece of paper or exercise book, a pen, pencil and your brains, because we're going to be doing a lot of new learning in today's lesson.

Let's start by going through the key words.

These are the star words for today's lesson and we're going to call them out using my turn.

and then your turn, are you ready? Freshwater, saline, glaciers, icecaps, solid, liquid, gas, evaporation, condensation, precipitation.

That one's quite tricky, let's do it one more time.

Precipitation, good job runoff, fantastic.

I'ma give you a second, just to look at those key words for today's lesson.

First, we're going to look at the question, where is Earth's water? Earth's water is almost everywhere, above the Earth, in the air and clouds and on the surface of Earth.

In rivers, oceans, in ice, plants and in living things like you and I.

Now let's have a look at the diagram to find out whether the Earth's water exists? Let's look a little bit closer.

The bar chart shows how almost all of Earth's water, 96.

5% is saline.

Saline means it has salt in it.

What does saline mean again? Good, that it has lots of salt in it and it is found mainly in oceans.

Where is most of the Earth's water found? Look at the bar graph to help you.

Good, in the oceans, 96.

5% of all water is found in oceans.

Of that small amount, let's look a little bit closer.

Only 2.

5% is actually freshwater, which is water that we can actually use to sustain, which means to support human, plant and animal life.

Look at the diagram closely.

Approximately what percentage of Earth's water is freshwater? Water that we can actually use, use the graph to help you.

You should have said 2.

5% is freshwater.

Well done, you're doing really well interpreting data so far.

Now, let's have a look at the next bar.

This shows the breakdown of freshwater and is only the 2.

5%, which is a tiny bit at the very top of the first bar graph and is the freshwater only.

So the second bar graph, even though it's the same size, which seems a bit confusing, it's only showing the 2.

5 freshwater and is breaking that down even further.

As you can see, almost all our freshwater is locked up in glaciers, icecaps and in the ground.

So only 1.

2%, which is only a tiny percent of all freshwater is surface water, which actually serves most of life's need.

The rest of it is locked up in glaciers, icecaps and in the ground, good job team.

Finally, let's look at the third bar.

This shows the breakdown of that surface freshwater that we can use.

Most of the water is locked up in ice, let's look a little bit closer.

So you can see the bottom part of the third graph, where it says surface water and other freshwater.

Most of it is locked up in ice.

Moving upwards, you can see 20.

9% is found in lakes.

Rivers make up 0.

49% of surface freshwater.

Although rivers only account for small parts of freshwater, this is actually where humans get a large portion of their water.

So, just to summarise most our water comes from oceans, 96.

5%.

Only 2.

5% of the whole global water is freshwater, which is water we can actually use to sustain life.

If we look at the breakdown of freshwater, most of it it's locked in glaciers, icecaps and in the ground.

Only 1.

2% is surface water that we can actually use.

Finally, let's look at that graph to summarise, most of surface water is in ice.

However, 20.

9% is found in lakes and rivers make up 0.

49% of all surface freshwater.

I know that it's really tricky, looking at data and interpreting it, but that's what real geographers do.

So really well done for paying attention.

Now I would like you to show that you understand the diagrams by looking at these statements and deciding whether they are true or they are false.

Let's look at the first statement.

So, most of Earth's water is salty.

Is this true or is this false? I'm going to give you a few seconds to think about that.

Okay, so you should have said that is true because most of the water on earth is saline, which means it is salty.

So well done, if you've got that question right.

Now, let's look at the next statement.

Most of Earth's water is able to be used by humans.

Is this true or false? Okay, you should have said it's false.

Only 2.

5% of water is freshwater, which is water that we can actually use.

The rest of it is really, really salty or saline, well done.

Let's have a look at the next statement.

Nearly, 70% of the Earth's freshwater is frozen in glaciers.

A large river of ice that is usually found sliding slowly down a mountain or icecaps, which are thick layer of ice that covers an area of land.

Is this true that nearly 70% is found in places in glaciers and icecaps.

You might want to look at the bar graphs another time, just to double check before you say, whether it's true or false, I'm going to give you a few seconds.

Okay, so you should have said that is true.

And the reason it's true is because nearly 68.

7%, which is nearly 70% is trapped in glaciers and in icecaps.

Let's look at the next statement.

Most of Earth's water is underground.

Is that true or is that false? I'm going to give you a clue, you can look at the second bar graph to help you.

Okay team, you should have said that it's actually false.

And the reason this is because if you look at the second bar graph, you can see that most of freshwater is actually found in glaciers and in icecaps and only 30.

1% is underground.

So, we can use that data to help us decide whether it's true or false.

Finally, there is more freshwater in rivers than in lakes.

Is this true or is this false? I'm going to give you a little clue, look at the third bar graph to help you with this one.

Okay, so you should have said false.

And the reason this is because rivers is only 0.

49%, whereas lakes are 20.

9%.

So there's more freshwater in lakes than there are in rivers.

Well done geographers, you have done a really good job at interpreting some data.

Now it's your turn to have a go at a task.

For this task, you will need to match up the water store with the correct percentage.

For example, let's look at the total global water.

Under that you can see is the option of oceans.

Now, I need you to think back to the bar graphs that we were just interpreting and I know that oceans make up 96.

5%.

So I can match those two together.

Pause the video now and complete the task on the screen.

The task is really going to challenge you, so give it your best shot.

Did you get the right answers? Well done, if you did.

We know that oceans make up most of the Earth's water so that is the largest percentage.

So, even though we might not remember the exact percentage, we do know it's above 90%.

So we can use that to estimate and pick the correct answer.

This was a tricky question, so if you challenge yourself to have a go at all of these, really well done.

I'm just going to leave this up for a second, so you can Mark your answers.

Okay team, now we are going to look at different states of matter.

There are three different states of matter, solid, liquid and gas.

Water can be a solid or liquid or a gas.

For example, when it's a solid, it is an ice cube.

When it's a liquid, it's like running water.

And when it's gas, it can be water vapour.

For example, water and other liquids can change state depending on the energy that the particles have.

On the screen, you can see the particle diagrams for solid, liquid and gas.

Notice that for the solid, the particles really close together.

For the liquid, they are some are touching, but some are further apart.

And for gas, the particles are not touching and they're really free to move.

When water becomes very cold and goes below zero degrees Celsius, it will freeze and become ice.

What will it become? Good job, it will become ice.

Ice is a solid, ice is a, good a solid.

And remember in the solid, the particles are really close together.

We call this a change in state.

The liquid, water has become ice.

So has turned from a liquid to a solid.

And we can show that with an arrow to show that it's changed states.

Now let's look at what happens when heat is applied to water.

So think about when you boil some water in a pan or a kettle or someone at home might do that, an adult.

The water becomes water vapour.

So this is the steam that you can see this coming off is water vapour and this is a gas.

So in this example, when you start heating water, liquid becomes a gas.

And in this case it becomes water vapour.

Remind me again, liquid turns into gas when it is heated, good job.

Now it's your turn to have a go, pause the video now to have a go at the task on the screen.

Remember to use the diagrams to help you.

How did you do this time? Well done, if you've got that answer correct.

Have you ever wondered, why puddles disappear on a hot day? It is because of evaporation.

My turn your turn, evaporation.

Evaporation is when a liquid turns into a gas.

When a liquid turns into a, a gas excellent job.

And this is called evaporation, well done.

Evaporation is when the liquid turns into gas.

Now on a hot day, the water absorbs the heat energy from the sun.

The heat then causes the water, which is a liquid to evaporate, which means it turns into a gas called water vapour.

Can you remind me, what is this gas called when it evaporates? Good, water vapour.

So in this process, the water, which is a liquid evaporates because it's heated up with the sun's energy.

And it turns into a gas, which is called water vapour, good job.

For this task, I would like you to describe the change in state for evaporation by filling in the missing gaps.

Pause the video now to complete this task.

How did you do this time? Well done, if you remembered what evaporation is.

Now, let's have a look at another real life example.

When you are having a lovely hot bath or shower, what happens to the mirror or the window in the bathroom? Think for a second and then shout your answer out loud.

What happens to the window or to the mirror? That's correct, you might said, that you can see that it is wet or that it has little water droplets on the surface.

Now, let me explain the science behind this.

When the warm steam from your shower or your bath meets the cold surface of the mirror or the window, it cools down.

It, good it cools down.

And so it condenses, my turn your turn, condenses, good job.

It condenses to form water droplets.

So the water that you can see on the mirror is the hot steam, cooling down and condensing to make little water droplets.

This process is known as condensation.

My turn your turn, condensation, good job.

This is when steam turns from a gas into a liquid.

What does it go from? Good, a gas into a liquid.

So condensation is a small water droplets, and it is liquid water on your mirror or your window, when you have a bath or a shower.

Pause the video now to have a go, at the task on the screen.

Remember to use the diagram to help you.

Did you realise that this statement was false? If you did, really well done.

Condensation is when water vapour, which is a gas, becomes a liquid, not a solid.

Water on earth is constantly moving.

It is recycled over and over again.

This recycling process is called the water cycle.

Let's have a look at the first part of the water cycle.

The sun heats up water on land, in rivers, lakes and seas and turns it into water vapour, which is a gas.

Can you point to the ocean and rivers in the diagram for me? Good job, so when the water heats up, the water vapour rises into the air.

It does what? Good, it rise it into the air and this process is called evaporation.

What is it called? Evaporation, fantastic.

So step one is that the water evaporates into the air from the oceans.

And this happens because of water heats up because of the sun's energy or we call it solar energy.

Now it's time for me to test you to see if you're paying attention.

What three labels are missing on the diagram of the water cycle? Did you say solar energy, evaporation and ocean? Well done team, you are showing some great listening and you're really paying attention.

Let's now have a look at what happens next.

Water vapour, which is the gas, in the air now cools down and changes back into tiny droplets of liquid water, forming clouds.

Put your finger on the keyword condensation, fantastic team.

So number two represents condensation, this is when the water vapour cools and turns back into liquid water droplets.

I would now like you to pause the video, to have a go at the task on the screen.

Here is the answer, did you choose the correct option? Well done, if you did.

Let's now have a look at the third step in the water cycle.

The clouds now get heavy and waterfalls back to the ground in the form of rain, snow, sleet or hail.

We call this precipitation, my turn your turn, precipitation.

Excellent job team.

So can you remind me, in what forms can precipitation come down in? It can come down as rain, snow, sleet or hail.

So well done, if you said any of those.

Now again, it's time for me to test you to see if you're paying attention.

What three labels are missing on the diagram of the water cycle.

Okay, you should have said condensation, evaporation and precipitation.

Well done, if you manage to get any of those answers.

Now for next your brand new point, can you tell me an example of precipitation? Great recall, you might have said rain, snow, sleet or hail.

You are doing a great job at remembering these new key words, well done everyone.

In the final stage of the water cycle, the water now returns to the ocean.

Rain water runs over the land and collects in lakes or rivers, which take it back to the ocean.

The cycle then starts all over again.

This is what I meant when I said water gets recycled.

Now that should make more sense to you.

Thank you for all your effort, so far team.

You are now ready to challenge yourself to remember as many of the key words as possible in the water cycle.

I wonder, who is up for that challenge? For this task, I would like you to write down the numbers and the correct key words that goes in that position on the diagram.

Pause the video now to complete this task.

How did you do this time team? Take a few moments to see if you matched up the correct number with the correct key word.

How did you do, did you get most, if not all of these correct? Wow, I am so impressed.

You are really talking like geographers now.

Is now time for you to complete the end of lesson quiz.

Enjoy the rest of the day, everyone.

And I can't wait to see you in lesson two, where we will be learning more about the weather and the climate, bye everyone.