Lesson video

Hello, everyone, and welcome back to another lesson with me, Miss Sidenius.

Today, we're going to be following on from lesson two, by becoming scientists and carrying out our own float and sink experiment.

Now that we know some objects float and some objects sink, it's time to put them to the test.

So we're going to start our lesson today by going on an object hunt to find some objects that we can test, then we're going to carry out our float or sink experiment.

And finally, we're going to share the results of our experiment with somebody in our household, a teddy or a toy.

In this lesson, you're going to need four things, a bowl of water, some objects, some paper and a teddy or a toy.

Now, we're going to do the objects later, but make sure you've got your water, your paper and your teddy or your toy ready for this lesson, and come back when you're ready.

Now, in this lesson, we're going to be scientists and we're going to carry out an experiment.

So we need to do our star words to make sure that we understand what everything means.

Star words, star words, star words.

We're going to carry out an experiment.

Experiment.

An experiment is a test to find something out.

So we're going to be finding out if objects float to the top of the water or they sink.

Waterproof.

Waterproof.

We're going to be testing waterproof objects where it doesn't matter if they get wet because they don't let the water through.

Float.

Float.

When something floats, it rests on the surface on the water, of the water, it rests on the top of the water.

Sink.

Sink.

When something sinks, it gets submerged by the water and it goes down to the bottom of the water.

So, what objects can you find in your house to put to the test? I found a plastic ball.

I found a shell.

You can see, I found a metal spoon.

I found a sweetie in a plastic wrapper, a plastic pen, some fruit and some green paper.

Now, I know that paper isn't waterproof.

It does get ruined when it gets wet, but I'm only using one small piece and I know that I have lots more, so it doesn't matter.

So, go and have a hunt around your house and see what objects you would like to put to the test.

Pause the video here and come back when you're ready? Well done, everyone.

I hope you found lots of different objects that you can use today.

Now, having a look at my objects, I'm going to predict which ones I think will float or sink.

Predict means I'm going to guess which ones will float or sink.

Hmm, I think that the paper will float because, even though it's a very big piece of paper, it's very light when I pick it up, so I think the paper will float.

And I think the spoon, hmm, the spoon is made from metal and it's quite heavy when I pick it up, so I think the spoon will sink to the bottom of the water.

Hmm, so what about the fruit? I think the fruit's quite heavy, as well, so I think the fruit will sink to the bottom.

And the other thing I'm going to test is the shell, and the shell is quite big and heavy, as well.

So I think the shell is going to sink to the bottom.

Let's put our objects to the test.

I'm starting with my spoon.

I hope you can see that.

It's gone under the water.

It's gone to the bottom.

My spoon sank to the bottom.

So I've got two circles out.

I've got one that says float and one that says sink, and I've put the spoon in my sinking circle.

Now I'll put my apple.

It's not under the water.

My apple was floating on the top of the water.

I was surprised by that.

I thought it would sink.

Let's try the banana.

Oh, ooh.

I predicted that the banana would sink because the banana was very heavy, but actually it floats.

Okay, let's try my shell next.

Oh, okay, I was right about the shell.

The shell does sink to the bottom.

I'm putting the shell with my spoon in the sinking pile.

What about my paper? Oh, and I was right about my paper, as well.

The paper floats because it's very light, and, even though it was a big piece of paper, it floated on the top of my water.

Now it's your turn to do your experiment.

Pause the video here, test your objects and come back when you're ready.

Now it's time to record our results.

I've made something called a table to help me record my results.

So, in the first column, I'm going to draw a picture of my paper, and for material I've put a puh for paper.

Eh, I've said my prediction was that the paper was going to float because I thought the paper was very light, so it was going to float on the water.

My prediction was what I guessed before I carried out the experiment.

Well let's see, was I right? I was, so I've put a tick in the final column because I was right.

The paper did float.

Next, I tested the spoon, ah.

Then I've put an mmm for metal because the spoon was made of metal.

And my prediction was that the metal spoon was going to sink to the bottom of the water because it was really heavy.

Was I right? I was.

The metal spoon did sink.

So I put a tick next to my spoon.

Next, I've got my banana and my apple.

Now, for material I've put puh because bananas and apples are food, so I've said their material is, puh, plants.

And my prediction was that they would sink to the bottom of the water because they are quite heavy, as well.

So I'm right, though? No, so I put a cross in my box there.

My prediction was wrong.

And finally, I tested my shell and I've put sss for material because it's a shell material.

And my prediction was that it would sink because it was very big.

Was I right? I was right.

Yes, the shell did sink to the bottom, just like the shells in the sea.

So, pause the video here, record your results and come back when you're finished.

So, how does it work? Why do some things float and some things sink? Well, objects are made up of lots and lots of molecules, which are like the red dots that you can see in the picture.

We can't see the molecules because they're inside the object.

That's what the object is made up of.

But some objects have molecules that are very, very, very close together, just like in the picture on the right.

Molecules are very close together here.

And, in some objects, the molecules are really far apart, like in this picture here.

When the molecules are close together, those little red dots, then it makes the object heavier, and it sinks to the bottom.

But when the molecules are far apart in the object, it makes it lighter, and those objects float to the top.

So, do you think my banana had molecules that were really, really close together and heavy, or far apart and light? What do you think? Right, I think they must've been far apart because my banana floated to the top.

It was light.

Well done.

Great job on today's lesson, everyone.

I hope you enjoyed finding out about floating and sinking as much as I did.

Don't forget to share your work with somebody in your household, a teddy or a toy.

I bet they would be really interested to find out more about floating or sinking, as well.

If you would like, you can also ask your parent or carer to share your work on Twitter with the @OakNational and the #LearnWithOak.

Bye, everyone.