Hello, scientists, my name is Mr. Wilshire and in this lesson we are going to be looking at soluble and insoluble.

The outcome for this lesson is, "I can compare materials based on whether they are soluble or not." As always, there are some key words for us to consider as we work our way through the lesson.

The first is dissolve, then it's solid.

After that is liquid, then it's soluble.

Finally, insoluble.

I wonder if you've heard of any of these words before.

Don't worry if you haven't, because the definitions have appeared on the screen for you now.

You can take a moment here to pause the video and recap on any of the words that you're not so sure on.

Pause the video now and restart when you've done that.

The first part of this lesson is called dissolving.

Jacob is helping his brother mix some sugar with water to offer to a tired bee.

Have you ever done this before? Bees can get very tired, especially if they have to fly in lots of places during the spring and the summertime.

They're working very hard to be able to get lots of pollen.

Sometimes you can find them exhausted on the ground, so giving them a solution of water and sugar is gonna give them that sugary boost.

It's a little bit like an energy drink for a bee.

After stirring the sugar into the water, Jacob is a little bit puzzled.

He says, "Hang on, I can't see the sugar anymore." Did Jacob forget the sugar? What do we mean by that? Pause the video here and discuss, restart the video when you've done that.

What did you discuss? Do you think Jacob really forgot the sugar? Stirring it got something to do with it? Well, let's find out some more.

The sugar is in the cup, but Jacob can't see it.

His stepdad explains that the sugar has dissolved into the water.

Some solids will dissolve in liquids, and then they form a solution.

Here you can see that the sugar is a white, opaque, solid.

Although it doesn't look like a solid, it is.

It's just got very, very small and tiny grains.

The water is a colourless and clear liquid.

The solution is also a colourless and clear liquid.

What do we mean by a solution? Well, a solution is where two items are mixed together to make one item.

Let's find out more.

Jacob says, "Has the sugar melted into the water?" What do you think? Is that really what's happened? Has it melted? Discuss.

Melting and dissolving are not the same thing, although I can understand why you would think that they would be very similar, because in both cases, something is disappearing by doing something, in melting's case, it's heating it up.

In dissolving's case, it's mixing it.

In both cases, something has disappeared to end up with a solution.

Melting happens when solid sugar gets hot and turns into a liquid.

There you can see solid sugar and we add some heat, that equals liquid sugar.

The liquid is still pure sugar.

We've not mixed it with anything else.

Dissolving happens when sugar in a liquid breaks into tiny pieces, which are too small and too spread out to see.

So, like we said, the sugar is still there, but it's been broken down into even smaller pieces.

Before we said that sugar was definitely a solid, it's just that you couldn't see it that well because it was very small.

Well, it's the same thing here.

When you take solid sugar and you add some water, mixing it up, it creates a water and sugar solution.

So the resulting mixture of water and sugar is called a solution.

Remember, that's when two or more objects will come together to form something new.

When a solid dissolves, it's broken down to become so tiny that we can no longer see it, but it is still there.

Jacob says, "Dissolve sounds a bit like disappear.

Does dissolve mean the same as disappear?" What do you think? Well, the sugar crystals haven't disappeared.

They have broken down into very small and tiny pieces, which are spread throughout the water.

You'd need a microscope to be able to see them up close.

You often can't tell just by looking whether a liquid has a solid dissolved in it.

The sugar and water solution looks just like the water did all by itself.

It's a colourless and clear liquid.

However, if you use brown sugar, which is a brown, opaque solid, the solution is a brown, clear liquid.

Here you can see two sugar solutions, one made with caster sugar and one made with brown sugar.

So you can see there that the brown sugar has created a sort of a murky brown sort of colour.

It's not as easy to see through, is it? Solutions are always clear, although they may or may not have a colour.

Izzy is talking to her sister about dissolving.

Izzy's sister says, "Is it only the water that can be used to dissolve solids?" And Izzy says, "Things can dissolve in other liquids too." Let's stop and think for a moment.

Some solids dissolve in liquids to form a what? Read each of these statements and decide which one best fits.

The correct answer here is a solution.

Some solids dissolve in liquids to form a solution.

True or false? Solutions are always clear and colourless.

The answer here is false.

Can we justify our answer? Which of these two statements matches? The correct answer here is solutions are always clear, although they may or may not have colour.

When a solid dissolves in a liquid, why can't we see the solid anymore? Is it because it's melted and become the liquid? Is it because the pieces are too small and too spread out? Or is it because the pieces have disappeared and are no longer in the liquid? The correct answer here is B, the pieces are too small and too spread out.

That's why we can't see the solid anymore.

This is your first task.

Match the words to their definitions.

You've got the words dissolve, liquid, solution and solid and some different definitions there.

Well, here's your task.

Best of luck matching up the words to their definitions.

See you in a moment.

How did you get on? Were you able to match each of these words up to their different definitions? Dissolve matches with this, "To mix so completely with a liquid that it cannot be seen." Liquid matches with this, "Something that can flow, takes the shape of its container and is not a solid or a gas." Solution matches with, "A liquid containing a dissolved solid in it." And solid matches with, "Something that holds its shape and is not a liquid or a gas." Well done for completing that task.

The next part of this lesson is called Soluble and insoluble.

At the beach, Izzy notices that the water in the sea tastes very salty.

This is strange because Izzy can't see any salt in the water.

She scooped the water out and had a good look, she can't see any salt in there.

She says, "Salt is soluble.

It's dissolved in the water to make a solution." And there you can see an image of the seaside.

Izzy's sister is making a sand castle.

There you can see a beach bucket.

She's mixed some sand and some water into a bucket.

Izzy says, "I know that solids dissolve in liquids, but I can still see the sand in the bucket of water.

Why didn't it dissolve?" Do you know? Discuss this.

Why didn't the sand dissolve? Well done for discussing that.

Let's look into that a little bit further.

Not all substances dissolve in liquids.

"If substances that dissolve are called soluble, then I wonder what substances that don't dissolve are called.

Are they unsoluble or non-soluble?" Hmm.

Unsoluble is incorrect and so is non-soluble.

What do you think? What do you call them? Well, substances that can't dissolve in a liquid are said to be insoluble in that liquid.

So let's see an example of something that does dissolve and maybe something that doesn't dissolve.

Izzy, for example, is making an orange flavoured drink using some powder.

She measures out 100 millilitres of water.

She's measured it out into a cup there, nice and accurately, to make sure that it's ready for her test.

She adds one teaspoon of orange flavoured powder to the water.

Hmm, maybe she's making a orange juice sort of drink.

She stirs the water and orange flavoured powder for one minute to help the powder to dissolve.

Sometimes dissolving can be sped up if you are there to stir it or mix it together.

Sometimes if you don't stir the items, then it can't really dissolve very well.

Sometimes it needs a bit of an extra help so it doesn't form a big, powdery base at the very bottom of the glass.

Sometimes with these sorts of powder, you need to give them a good stir to make sure that they dissolve, or otherwise they'll form a bit of a powdery base at the bottom of the glass.

Izzy observes to see if the solid powder has dissolved into the liquid water.

She's having a good look there to make sure that everything's dissolved into the water.

The powder has dissolved, so that means that the powder is soluble.

If something can dissolve, it's soluble.

If it doesn't dissolve, it is insoluble.

Remember that a solution is in clear water, but it may or may not have a colour.

Jacob wants to do the same kind of thing, but he wants to test some other items. He wants to investigate which solids from his kitchen cupboard dissolve in water.

Hmm, I wonder what he means? What kind of solids can you think of? Have a quick think about different solids you might find in a kitchen cupboard.

What did you think of? Maybe you thought of some pasta or some rice, maybe.

Which of those items are going to dissolve, I wonder? Could Jacob use Izzy's method to investigate this? Have a good think here.

Izzy has been really methodical in her approach.

She's stirred for exactly a minute.

She's made sure that she's got an exact amount of water.

Could Jacob use Izzy's method here? I think that Jacob really could use Izzy's method.

She's been very accurate with the amount of water that she's putting in.

She's used one teaspoon of powder.

So if the children were to do this as an experiment, it would be a good idea to separate different items out and to measure it.

That way we can ensure that it's a fair test.

It wouldn't be very fair to measure something dissolving in 200 millilitres of water.

That's a lot more water, isn't it? So it might speed up the dissolving process or might change the outcome altogether.

When you're creating your own experiments, it's a good idea to think of the different variables.

You always have to control something and change one thing, but that's the only thing that you can change.

Otherwise, it will lead to a bit of an unfair test and you'll have very different results, which might not make sense.

Let's stop and think.

Which word describes a substance that dissolves in a liquid? Is it insoluble, solution, solvent, or soluble? The correct answer here is soluble.

The word that describes a substance that dissolves in liquid is soluble.

Which word describes a substance that does not dissolve in a liquid? Is it solution, insoluble, soluble, or solvent? The correct answer here is insoluble.

The word that describes a substance that does not dissolve in a liquid is insoluble.

Here's task B.

It's your chance to investigate.

This is kind of what we discussed earlier.

Investigate which kitchen solids dissolve in water.

Use Izzy's method or plan your own.

For each solid, record whether it was soluble or insoluble.

You may like to record your results in a table.

Group which solids were soluble and which were insoluble.

Izzy says, "Remember, if a solid dissolves, the solution will be clear and colourless." So there's your task.

Have a good think about the different items that you could use.

You could use sugar or salt.

You could use some flour, maybe.

There's lots of things you could find in a kitchen cupboard.

So have a go at this task and restart the video when you've done that.

Here's some answers, yours may have been similar.

The soluble section there, there's sugar and there's salt.

The insoluble section, it says sand, cornflour, margarine, mustard powder, a biscuit, flour, and pepper.

Solids which were soluble in water are on the left and the solids that were insoluble are on the right.

Were your answers similar or were they different? I wonder which other items you found inside the kitchen cupboards.

Maybe you had a go with the rice or some pasta, like I said earlier.

Hopefully you're able to follow the experiment and make sure that it was fair each time, making sure that you had the same amount of water and that you stirred for the same amount of time.

In this way, you'll ensure that there's a fair test and that your outcome and that all your results are easy to be looked through and compared with each other.

Let's summarise our lesson.

Some solids dissolve in liquids to form a solution.

Solutions are always transparent, although they may or may not have a colour.

When a solid dissolves, it's broken down to become so tiny that we can no longer see it, but it is still there.

A substance that dissolves is said to be soluble and a substance that does not dissolve is said to be insoluble.

Hopefully you've enjoyed those two tasks.

Well done for completing them.

You should have a good idea as the differences between something that is soluble and something that is insoluble.

I wonder how it might help you in your future working life.

This is really good knowledge to know if you're trying to create your own types of snacks or drinks in the future.

You'll need to know which things are going to dissolve or otherwise your guests, if they're drinking something, are gonna end up eating something, which I don't think they'd particularly enjoy.

I've been Mr. Wilshire.

Thank you very much for listening.