Lesson video

- Hi, folks, my name is Mrs. Farrow.

For today's session, you're going to need a pen and a piece of paper, and it's a good idea to switch off or silence any mobile devices to help avoid distractions.

If you'd like to take a few minutes to sort those things out, press Play when you are ready to resume.

So today's session is going to be about metals and non-metals.

We're going to describe some of the common properties of both metals and non-metals and how we use different materials based on their properties for different uses.

So let's move on and take a look.

Some of the keywords that you will encounter during today's lesson include malleable, these are substances that can be bent or hammered into shape without breaking, a conductor, which is a material that lets heat or electrical energy pass through it, and materials that are hard but can break easily are referred to as being brittle.

We've broken today's session down into four sections.

Those are, what are properties, properties of metals, the properties of non-metals, and then some of the uses of metals and non-metals.

So if you're ready, we'll jump straight in and take a look at what are properties.

Well, a property is a characteristic of a substance.

It's how we describe how it looks, behaves and reacts.

Some common properties that we often talk about of different substances include things like melting point.

Really important that we're careful here with our language.

Lots of students when asked to say what melting point is will say, "Well, it's the point at which something melts." You're entirely not wrong, it is, but we're not adding any value, we're not actually adding a scientific explanation to what the phrase means, so we need to be careful that we are using the phrase, the temperature at which a solid changes to a liquid, okay? So a melting point is the temperature at which a solid changes to a liquid.

We then have boiling point, again, the same issues is often seen here.

We should be saying that it is the temperature at which a liquid changes to a gas, so we're being really specific about what state change is occurring and the idea that it is at the temperature that that is occurring.

And then finally, conductor.

So if something is a conductor, it's a material that is going to allow electrical or heat energy to pass through it, this being the opposite of insulators, which you may have looked at, which don't allow either heat or electricity to pass through them.

So, some important keywords there regarding properties which relate to our metals and non-metals that we're going to look at moving forward.

So let's do a little quick knowledge check and see what you can recall.

So we've got True or False.

The melting point is the temperature at which a solid changes to a gas, True or False? Hmm, okay, so this is tricky because the melting point is a temperature, so the first little bit of that sentence is correct, but then it says, at which a solid changes to a gas.

Well, when something's melting, it's changing from a solid to a liquid, so we should have said that this statement is false.

Our reasoning for that is, melting is the process of changing from solid to liquid, not solid to gas.

Well done if you've got that one right.

Now it's time for you to have a go at a practise task.

You'll want to pause the video now in order to complete this task to the best of your ability.

We're asking you to draw lines to match up the keywords to the correct definition.

Press Pause, and when you're ready to hear the correct answers, you can restart the video.

So let's take a look and see how you got on.

Melting point.

Now we talked about this in some detail.

The melting point should be matched to the temperature at which a substance changes from a solid to a liquid.

We've then got boiling point.

This is the temperature at which a substance changes from a liquid to a gas.

And then finally, conductor.

This should be matched with a material that allows heat and electrical energy to pass through it.

Well done if you've got all of those right.

It's really important to practise our key terms and definitions as it enhances your science writing to use these phrases as much as possible.

Right, so now we've taken a look at properties, it's time for us to apply our learning and look at some properties of metals.

Properties of metals include being solid at room temperature.

They tend to be very strong, this makes them incredibly useful as building materials.

They're conductors of both heat and electricity and so are useful in terms of, in the kitchen, when we are looking at making saucepans or baking trays, and conduct electricity, we use them in our wires and electrical devices often.

They tend to have a high density.

This means that they have a large mass per given volume.

That's quite a tricky idea to get our heads around, but what it ultimately means is that they're likely to sink when placed in water.

They are shiny and reflect light and so look pretty when making things like jewellery, and they tend to have very high melting and boiling points.

This means we need to get them really hot in order to change their state.

So being solids at room temperature, we need to get them very hot in order to melt them to liquids, and even hotter again in the hope of getting them to change to a gas.

Now metals have some unique properties which make them very useful to us as well.

They are malleable.

Now malleable means that can be bent and hammered into shape without breaking.

I'm sure many of you have had the odd paperclip and sat and bent and fiddled with them, and you'll notice that you can twist them into many different shapes without the paperclip from breaking, and this is because it is a malleable material.

Metals are useful because we can hammer them into lots and lots of different shapes and therefore use them for a variety of different things.

Metals are sonorous.

This means that they make a ring or ping sound when struck.

This is why numerous musical instruments are made of metal.

If you think about the cymbals as part of a drum kit, they make a lovely tinking noise when hit with the drumstick.

A gong made out of plastic would be no good.

It would make a dull thud as opposed to that lovely crashing noise.

And then finally they are ductile, which means that they can be drawn into wires.

This is particularly useful, being as we know that they can conduct electricity.

The layers in the metal allow the atoms to slide over one another, and this is what allows them to be drawn out so very thin in order to make the small electrical wiring that we need in components such as our mobile phones and laptops.

Let's do a quick knowledge check then.

What do we call the property of a substance that can be bent or hammered into shape without breaking? Is it, A, sonorous, B, malleable, C, brittle, or D, dense? The correct answer is B, malleable.

What does sonorous mean? Is it, A, it can be drawn into wires, B, it makes a ringing sound when struck, C, can be bent and shaped without breaking, or D, melts at low temperatures? The correct answer is B, it makes a ringing sound when struck.

Well done if you were able to get that one right.

What do we call the property that means a substance can be drawn into wires? Is it A, sonorous, B, malleable, C, brittle, or D, ductile? The answer to this question is D, ductile.

The metal is able to be drawn into wires as the atoms are in layers and slide over each other.

Now it's time for a practise task.

We'd like you to pause the video and spend some time defining, writing the meaning, of the following key terms, sonorous, malleable, ductile.

When you're ready to hear the answers, press Play.

Shall we take a look at how you got on? Now you don't have to have written these word for word the same as mine, but it does need to follow the same general scene.

Sonorous, then.

What does sonorous mean? Well, it's a description of a material that makes a ringing sound when struck.

Remember those cymbals? Malleable.

Malleable is a material that can be bent or hammered into shape without breaking.

And then lastly, ductile.

A material that can be drawn into wires.

These are all important properties of metals only, and this is what makes them particularly useful for certain roles that we require them to do, which we're gonna take a look at later.

We've had a look at properties and the properties of metals, now it's time to jump into the properties of non-metals.

The properties of non-metals include, they tend to be liquids or gases at room temperature.

They are brittle, this means that they break easily if they are solids.

Things that are brittle tend to be quite crumbly.

They are poor conductors of heat and electricity, often referred to as insulators.

We often use them around our electrical wires in order to insulate electricity, and most of our clothes are insulators too.

They have a low density.

This means they have a small number of particles per given volume and so will often float in water.

They are dull and do not reflect light easily.

They are not ductile and so cannot be drawn out thinly into wires.

And they have low melting and boiling points, so only slight heating is enough to often change them from solids into liquids or gases.

Let's do a quick knowledge check then.

Non-metals are poor conductors of electricity.

True or False? The correct answer to this question is True.

Non-metals do not allow electricity to pass through them and so they are considered poor conductors.

Good job if you've got that one right.

Next question, select the two properties of non-metals, so we're going to pick two of the following list.

A, brittle, B, shiny, C, low melting points, and D, high density.

The correct answers are, A, brittle, and C, low melting points.

Now it's time for a practise task.

The first part of this task asks you to delete one of the options in the brackets so the sentences read correctly.

You'll need to pause the video now and give this task your full concentration and effort, and when you think you're ready to hear the answers, press Play to resume.

How did you find it? Let's see how you got on.

Sentence number one, non-metals cannot usually conduct electricity.

Sentence two, non-metals have a low density.

Sentence three, non-metals are poor conductors of heat energy.

Sentence four, non-metals are brittle.

And sentence number five, non-metals have low melting and boiling points.

Give yourself a tick for each question.

How many did you get right out of five? Lots of them, I'm sure.

Don't worry if you've struggled with any aspects of this though, you can always go back and watch this section again if you need to.

Task B asks you to put a tick in the correct box to show if the property belongs to a metal or a non-metal.

Again, it's a good idea to pause the video and give this task your full attention and a bit of time.

When you're ready to hear the answers, press Play and we'll go through them together.

Let's see what you've got right then.

So the property, malleable, this belongs to metals.

Something which has a low melting and boiling point easily changes from solid to liquid to gas.

This must be a property of non-metals.

The substance which conducts heat.

I know this one from personal experience having burnt myself on metal spoons I've left in saucepans before.

This is a metal.

Brittle means it can easily be broken.

As metals are malleable, this must apply to non-metals.

And finally we have shiny, which is a property of metals.

Well done if you've got all of those right.

Where are we on our journey? Well, we've taken a look at properties, the properties of metals and the properties of non-metals.

Now it's time to dive in and taken a look at some of the uses of metals and non-metals and how they link to the properties we've already seen.

So objects are made from different materials.

The materials are selected based on their properties.

So, for example, we use metals to make electrical cables because they have the properties of being a conductor of electricity and ductile.

It will be no good trying to use a non-ductile, brittle insulator in order to make electrical cabling.

Non-metals are used to make things like insulation that we find in our cavity walls and our lofts.

This is because they are poor conductors of heat energy and so much more effective at keeping our homes warm.

Filling our roofs and cavity walls with metal would be a mistake, as they would easily conduct the warmth out of our homes.

Let's take a look at an everyday object like a frying pan.

If we take a look at the base of the frying pan, you can see it's made of metal.

Metals are good conductors of heat and have very high melting points.

These are important properties, because we don't want our frying pan base to melt when we put it on a high heat, but we do need it to allow the heat to pass through in order for the food that's inside it to cook.

The handle, on the other hand, is often made of a non-metal, like a plastic, because non-metals are poor conductors of heat.

This means the handle stays cooler and safer to hold.

You may have saucepans at home which have metal handles and you'll have to be very careful when picking them up, perhaps using a cloth in order to avoid burning your hand.

Why don't we make the whole frying pan out of non-metals? This is an easy one to answer.

Can you imagine if your frying pan was made out of something like plastic? You're going to get an awful sticky mess on the hob when trying to fry an egg.

Let's do a quick knowledge check and see what we can recall.

True or False.

Metals are used in electrical cables because they are sonorous.

True or False? These true or false questions are tricky.

Part of this statement again is correct, metals are used in electrical cables.

They are.

However, it then says because they are sonorous.

Now remember, that's one of our key terms, which means it makes a ringing noise when struck, so the answer to this question is, False.

Metals are used in electrical cables because they conduct electricity and they are ductile, not because they are sonorous.

Now it's time for a practise task.

You'll need to pause the video to give you these tasks your full attention.

The first one asks you to look at the image and complete the sentence and answer the question regarding the kettle.

When you're ready to hear the answers, please press Play.

Let's see how you've done.

The first task asks us to complete the sentence.

The jug is made from metal, because it is a good conductor of heat.

Then we're asked to explain why the handle is made of plastic.

Plastic is a non-metal.

It is a poor conductor of heat energy, or you could say insulator.

A person can touch the handle and it will not be too hot.

Well done if you got those right.

Remember, when we're answering in longer sentences, you don't have to have it written word for word the same, but you should have the same ideas within your sentences.

Let's take a look at the next task.

Draw lines to match the use with the property.

We have church bells, power cables, saucepan, and jewellery.

You need to select the most appropriate property from the list opposite to join it up with.

High melting points, sonorous, shiny, and conducts electricity.

Pause the video and have a go, and then we'll take a look together at the answers.

When you're ready, press Play.

How'd you get on? Let's have a look.

Well, church bells need to be able to ring out to call people to service and in celebration, so they need to be sonorous.

Power cables need to allow electricity to pass through them in order to charge our devices, and so they need to be able to conduct electricity.

A saucepan is going to be placed on the heat and so should have a high melting point, and jewellery needs to be shiny.

Well done if you've got all of those correct.

So we've reached the end of our session together today.

Let's take a look at some of our key learning points.

Materials are chosen to make different objects based on their properties.

Metals and non-metals have different properties.

Metals' properties include being shiny.

Malleable, meaning they can be bent and hammered into different shapes.

Strong and sonorous, making a ringing noise when struck.

Non-metal properties include having low melting and boiling points, and so don't require much heating to melt them or turn them into gases.

They are poor conductors or insulators and they tend to be very brittle.

Before signing off, why not have a go at our exit quiz? Well done, and thank you for all your hard work today, I really hope you've enjoyed this lesson.

We'd like to take this opportunity to thank you for using Oak National Academy and we hope to see you soon.

Bye for now.