Lesson video

Hello.

My name is Ms. Couves.

And I'm really looking forward to our science lesson today.

One of the things I've really enjoyed doing over the lockdown is having a barbecue in my garden.

When I'm cooking on the barbecue, there is a fuel being burned, and it is releasing heat to cook my food.

You can also see fuels being burned if your parents use a gas stove, or if you have a fireplace.

Have a think.

Can you remember a time that you have seen a flame? Well, that is exactly what we're going to talk about today.

We are going to learn about fuels and what happens when they burn.

So, today we're going to start by recapping some of our previous knowledge on the earth and sustainability.

Then we are going to look at what a fuel is and the reactions that fuels undergo during burning.

Finally, we will look at the impact of fuels on our environment.

For today's lesson, you will need an exercise book or paper, and a pencil.

If you don't have one of these items, pause the video now and go and get them.

The first thing I want you to do is try and remember as many things about natural materials as you can.

Pause the video and have a go filling in the information missing from this slide.

A natural material is a material that comes from a plant, an animal, or the earth, the ground.

An example of a material that comes from a plant is cotton.

An example of a material that comes from an animal is wool.

And an example of a material that comes from the ground is coal.

Now, let's think about a synthetic materials.

What is a synthetic material? A synthetic material, is a material that is made by humans.

We have three examples.

Can you remember what they are? Plastics, glass and ceramics.

In this unit, we've been thinking about sustainability.

Sustainability means meeting the needs of the present without sacrificing the ability of future generations to meet their needs.

There were three Rs that we could do to increase sustainability.

Can you remember what they were? Reduce, reuse and recycle.

When we think about the sustainability of different products, we use a life cycle assessment.

We looked at how lifecycle assessments were used to decide whether or not bringing your own reusable cup was better than using a takeaway cup.

What three things did we need to think about? How it is made, how it is used and how it is disposed off.

So, our new learning today is going to start with what is a fuel.

A fuel is a substance that can be burned to release energy.

We're going to look at an example.

So I've got my lab coat on and I've got my goggles on, and I'm going to show you an example of a fuel burning.

This is an experiment that you can't do at home.

I'm going to do it because I am a trained scientist.

I am going to burn a fuel.

My fuel is a match.

My match is made out of wood.

Is wood a natural resource or a synthetic resource? Wood is a natural resource because it comes from a plant, or tree.

When I burn my match, the wood is burning and is releasing heat.

A fuel is an, is a substance that can be burned to release energy.

Why is my match an example of a fuel? The match is an example of a fuel because it is being burned to release energy, and we feel that energy as heat.

There are lots of examples of fuels, including wood, coal, crude oil and natural gas.

Pause the video and write down the definition of a fuel and three examples.

Coal, cruel crude oil and natural gas are all highlighted on this slide.

This is because they're all examples of fossil fuels.

My turn, fossil fuels.

Your turn.

Fossil fuels are natural resources found in the ground.

They take millions and millions of years to make.

They are finite resources, which means that they will run soon.

Why is it a problem that fossil fuels are finite resources? It's a problem because that means that they'll run out, which means they're not sustainable.

We use fuels in our homes to heat them, to drive our cars and to generate electricity.

What are three things we use fuels for? To heat our homes, to drive cars and to generate electricity.

Let's test our knowledge.

There are three questions to test your knowledge.

Number one, what is a fuel? Number two, name three fossil fuels.

And number three, what are the fuels used for? Pause the video now and answer the questions, and your next.

Get another coloured pen so that you can check your answers.

Remember that you should tick a correct answer and correct an incorrect answer.

Number one, a fuel is a substance that can be burned to release energy.

Number two, the three fossil fuels are coal, crude oil and natural gas.

And number three, fuels are used to generate electricity and power cars.

So, let's think about combustion reactions.

A combustion reaction is the scientific word for burning.

My turn, combustion.

Your turn.

Great pronunciation.

So, let's have a look at our match again.

When our match is burning, scientists call this a combustion reaction.

In a combustion reaction, the fuel, what's the fuel in the case of my match burning? The fuel is the wood.

The wood is reacting with oxygen in the atmosphere to form carbon dioxide and water.

This reaction called a combustion reaction, releases heat.

It is the heat released by combustion reaction that is useful.

What did the fuel react with in the combustion reaction? The fuel reacted with oxygen in the atmosphere.

What was formed by the reaction? The products of the reaction were carbon dioxide and water.

Pause the video and define the key word combustion.

Combustion is the scientific word for burning.

Scientists represent combustion reactions using word equations.

When scientists write word equations, they write the reactants, so what they start with on the left hand side, and the product what they form, on the right hand side.

When a scientist reads a word equation, when they get to the arrow, they say the word produces because the arrow is telling you that the reactants produce the products.

So I would read this word equation as reactants produce products.

What do you say when you read a word equation and you get to the arrow? That's right.

Say the word produces.

What's the name of the things you start with in a reaction? The things you start with are called the reactants.

What's the name for the things you produce in a reaction? That called the products.

Pause the video and write down the reactants for combustion.

The reactants for combustion are a fuel and oxygen.

In my word equation, I've written fuel plus oxygen produces.

Remember that when I draw an arrow, say the word produces.

My turn, fuel plus oxygen produces.

Your turn.

Right.

On the other side of the arrow, write down the products of combustion.

So now, we've got a full word equation.

A fuel plus oxygen produces carbon dioxide plus water.

Let's try doing this from a match.

What was the fuel when we lit the match? The match was made out of wood so the fuel was wood.

The wood plus oxygen produces carbon dioxide and water.

What are the products for all combustion reactions? Carbon dioxide and water.

Well done.

So, let's have a go at writing the word equations for some different fuels.

We've got four fuels here, methane, propane, petrol, and diesel.

Pause the video and have a go at completing the word equations.

So, you should have gotten, methane plus oxygen produces carbon dioxide and water.

Tick if you've got it right, correct it if you've got it wrong.

Propane plus oxygen produces carbon dioxide plus water.

Petrol plus oxygen produces carbon dioxide plus water.

And diesel plus oxygen produces carbon dioxide plus water.

So, now we're going to think about what happens when we burn fuels to make electricity or to heat our homes, or to drive cars.

What was always produced in all of the combustion reactions? In all of the combustion reactions, we produced carbon dioxide.

Well, carbon dioxide is an example of a pollutant.

A pollutant is a substance that negatively impacts the environment.

If something negatively impacts the environment, does that mean that it's good for the environment or bad for the environment? It means it's bad for the environment.

So every time we burn fossil fuels, we produce carbon dioxide, which we know is bad for the environment.

The other thing that is produced by it, the other thing that is produced by fossil fuels when they're burned is hydrogen sulphide.

Hydrogen sulphide is produced because of sulphur impurities in the fossil fuels.

When they burn, they produce hydrogen sulphide.

Both of these products of combustion, negatively impact the environment.

They make the environment worse, that's why they're called a pollutant.

Pause the video and write down the definition of a pollutant.

A pollutant is a substance that negatively impacts the environment.

Two examples of pollutants are carbon dioxide and hydrogen sulphide.

So, our big question for today is, given that fossil fuels are finite, which means they run out and they produce pollutants that are harmful to our environment, do you think that we should be allowed to burn them? Discuss that question with your friends and family, see what they think too.

Well done with all of your learning today, you've worked really hard.

Make sure you take the quiz to check how much you know.