Science: Y4 Summer Term 2 Learning Pack

How should this pack be used?

Dear Parents,

This work and activities in this pack are as close to what we feel children will be able to achieve at home. It follows roughly the same learning order as what would have normally been taught in school. The way each unit is structured follows what we would normally do in lessons; introduce an idea, discover the knowledge and theory then conduct investigations to tests these. Some units include more theory than investigations so please follow this guidance (and use the checklist) for the work and learning your child should be doing:

1) Theory paragraphs and glossary Please tick when complete

Activities Unit 1 Unit 2 Unit 3 Unit 4 Must: children to create fact cards for each paragraph. Could be completed in writing journals.

Must: children to create key vocabulary cards (with definitions) for some of the words in the glossary.

Could: children to create an information poster and/or a PowerPoint showing all their key knowledge and understanding for each unit.

Could: children to create a quiz, using PowerPoint or a website like Kahoot.

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2) Practical ideas and investigations Activities 1 2 3 4 5 6 7 8 9 Must: if possible (thinking about the resources), children to have a go at each of the investigations in each unit. They can take notes in their writing journal about how it went and their findings.

Could: when carrying out the investigations, children to take photos ready to show and explain to their teacher.

Could: children to produce a ‘write-up’ of their investigation to publish in a science magazine including all of the different stages of an investigation (as they have taught about in school).

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Note: this learning and work are age-appropriate for your child, meaning it should have a fair level of challenge. Feel free to support or learn with your child as you work through the pack and to also use fantastic online learning sites (such as BBC Bitesize) to help.

Please note: The topic for this term is Electricity. There are some areas

on the Knowledge Organiser that are not covered in this pack as they do

not lend themselves to Home Learning.

Inside the pack there are activities all the children should be able to

access at home, also some bonus activities that your children will enjoy

taking part in.

Year 4: Electricity

Y4 Electricity:

Unit 1

Activity 1

The Big Picture Electricity is a vital part of modern life. It lights up our towns and cities, powers industry and keeps our trains moving. Most of the devices that we use in the home and the gadgets we carry around use electricity, either from the mains or stored in batteries.

Though electricity was previously known to humans through phenomena such as lightning or the behaviour of electric eels, it was only in the 18th century that it began to be understood and the 19th century before it could be generated by people as required. In the UK, it was well into the 20th century before electricity was supplied to all houses. Now it is difficult to imagine our lives without electricity.

Electricity is also involved in our bodies’ functioning – electrical messages are carried through the nervous system. Understanding this process allows doctors to monitor our heart and brain functions, and they can even regulate heart rates using tiny pacemakers.

Electricity continues to be an important topic area for research. Scientists are looking into greener ways to generate electricity to meet our growing demand for energy. They are developing better batteries to store energy, which would allow electric cars to go further on a single charge as well as make our smartphones last longer.

Electricity is the flow of tiny particles called electrons. The amount of electrons flowing is called the current. They can think of it like water flowing in a river – the faster the flow of water, the greater the current.

Electricity can only flow when a power supply is able to “push” the electrons around a complete circuit. This means a path is needed from the power supply through the components in the circuit and back to the power supply. The size of the push is called the voltage. The higher the voltage, the bigger the push moving the electrons around the circuit.

Electricity is a form of energy. It can be converted by circuit components, such as light bulbs, motors and buzzers, into other useful forms of energy like light, heat and movement.

Electrons do not come out of a battery or wall socket and are then changed into light, heat etc. The electrons are in all the parts of the circuit already. Imagine several children loosely holding onto the same plastic hoop. If one child starts moving part of the hoop, then the whole hoop starts moving. That child is like a battery, pushing electrons (the hoop) around the circuit. Electrons all start moving at the same time, like the hoop.

Understanding in the Real World We use electricity every day of our lives. Televisions and games consoles will

not work unless they are plugged in. Many toys need batteries to work and

come in different shapes, strengths and sizes.

Phones and tablet computers in the home need charging from time to time. There are batteries inside and that they need to be plugged into the mains to recharge.

Conductors and Insulators A conductor is a material that allows energy (heat or electricity) to pass through it easily. Metals are good conductors because their electrons are free to move from one atom to the next and take the energy with them. Wires are often made of copper because it is a good conductor of electricity.

An insulator is a material that does not allow electricity, heat or sound to pass through it easily. The electrons in insulators are not free to move or to carry energy from one atom to the next. Rubber, plastic and wood are all insulators.

Unit 2

Electrical Safety

Electricity is very useful but also can be extremely dangerous. Discuss the dangers with an adult to make sure you really understand them. Then complete the activities.

Water and electrical safety If water and electricity mix they can cause a nasty electrical shock. Electrical devices should not be used near sources of water. E.g. do not use a hairdryer in the bathroom.

Always dry hands completely Never touch anything electrical with wet hands. This includes flick light switches. Why do you think most bathroom lights are operated by a pull cord?

Do not put drinks or liquids on top of electrical appliances This is especially important when they are being charged up. Any spill could cause a shock, spark or fire.

Don’t shelter under a tree in a thunderstorm Or swim. Lightning is pure electricity.

Never stuff things into electrical sockets It is very dangerous to poke things into sockets. Plug protectors are often used to prevent young children from pushing things into them. When removing plugs always hold the plastic casing, never by the wire.

Know how to deal with electrical cables, cords and sockets Do not overload plugs and adaptors, they can overheat and cause a fire.

If you spot a faulty or damaged cable DO NOT TOUCH. Tell an adult. Avoid trailing cables over the floor, they can cause people to trip.

Look after electrical items when they are not in use Switch then off at the plug. They will be much safer and save any electricity being wasted.

Overhead power lines Never climb the pylons. If flying a kite, using a fishing rod, make sure you keep clear of pylons.

In the kitchen As well as knives and scissors, you should not use electrical items when adults are not around. Do not put tin foil or metal in the microwave, this could trigger an explosion Never stick anything metallic in the toaster.

You have just been appointed a Health and Safety Inspector – congratulations.

Your first task is to spot the hazards in this kitchen

Circle them and explain why they are a hazard. Include all hazards, not just the electrical ones.

Part of your new role is to prevent accidents from happening.

Make a poster to warn people of the danger of electricity.

How could you make a really good poster?

Things to consider: wording, size of writing, pictures/diagrams, slogans

Activity 3

Activity 2

Unit 3

Where Does Electricity Come From? Most of the electricity we use is created in power stations. The current leaves a power station through power lines and cables to reach our homes, our schools and our workplaces. This type of electricity is called mains electricity.

At the heart of all power stations are turbines and generators. A turbine is a machine that rotates as a fluid passes over or through it. Turbines are often connected to generators in order to convert this energy of movement into electricity.

A generator is a machine that turns kinetic energy into electricity by using a spinning magnet. A dynamo light on a bike is a good example of a simple generator. As the pedals and wheels turn, they spin a magnet that produces enough electricity to power the light on the bike. The generators in power stations or wind turbines are simply giant versions of a dynamo.

There are many different ways that electricity can be made. Traditional power stations use coal or gas (fossil fuels), or nuclear energy to generate electricity.

Solar panels, wind turbines, hydro-power are all other ways to make electricity.

A battery powers things with the electrical energy stored inside it. Some batteries are rechargeable, others you can only use once.

Now you need to complete an audit (survey) in your house of the electrical items. Fill in the sheet below, showing how the appliances receive their electrical current.

Mains Battery Other

Glossary 1. Circuit

The path around which an electric current circulates. An electric current will only travel around a closed, complete circuit.

2. Conductor

A material that allows energy (heat or electricity) to pass through it easily.

3. Current

The flow of electrons around a circuit. Current is measured in amperes or amps (A). The circuit must be complete in order for the current to flow.

4. Electrical Energy

Energy carried by electricity. Electrons carry electrical energy as they flow through a circuit.

5. Electricity

A type of energy that consists of moving electrons. When electrons flow through a circuit an electric current is created.

Activity 4

6. Electron

A tiny particle found inside atoms that has a negative electrical charge. Electrons orbit the nucleus of atoms. When electrons move from atom to atom, or flow around a circuit, an electric current is created.

7. Generator

A machine that turns kinetic energy into electricity using a spinning magnet. A dynamo light on a bike is a simple generator. As the wheels turn they spin a magnet, which produces enough electricity to power the light on the bike.

8. Insulator

A material that does not allow electricity, heat or sound to pass through it easily. The electrons in insulators are not free to move or to carry energy from one atom to the next. Rubber, plastic and wood are all insulators.

9. Mains Electricity

Electricity supplied directly from power stations to houses and other buildings.

10. Turbine

A machine that rotates as a fluid passes over or through it. Turbines are often connected to generators in order to convert this energy of movement into electricity.

11. Voltage

The “push” of a battery or power supply to create a flow of electricity. Voltage is measured in volts (V). The higher the voltage, the bigger the push.

Unit 4

Big Question: What Is Lightning? Have you ever heard a crackle or noticed little sparks of light when removing a jumper? Perhaps you have received a “shock” after touching a metal surface or another person. These shocks are the result of static electricity.

When you rub some materials together, it can cause electrons to move from one material to the other. This means that the material that loses electrons becomes positively charged and the material that gains electrons becomes negatively charged. If the two materials have the same charge they will repel each other. If the two materials have opposite charges they will attract each other. The atoms in materials will try to become neutral, so as the electrons flow back to their atoms a tiny spark may be seen or heard.

Lightning is also a type of static electricity, but the force of lightning is much more powerful. Lightning is created in a thundercloud when small bits of ice bump into each other as they move, transferring electrons to each other. All of those collisions make static electrical charges in the clouds.

Just like batteries, these clouds have positive and negative ends. The positive charges are at the top of a cloud and negative charges are at the bottom. When the negative charge at the bottom gets strong enough, the cloud releases energy – and lightning strikes!

The lightning travels through the air, attracted to a place that has an opposite charge. This could be another cloud or an object on the ground.

Although exciting to watch, lightning can be very dangerous. One bolt of lightning contains enough energy to toast 100,000 pieces of bread!

Big Question: How Does a Battery Work? If you look closely at a standard battery, you will notice that there are two terminals, or connections, marked positive (+) and negative (-), one at either end of the battery. If a wire is connected across these terminals, the electrons in the wire will all start moving from the negative to the positive end.

This is what happens in a battery-powered device, such as a toy car. The battery provides the energy, and electrons move between the terminals, providing the toy car with the electrical energy it needs to function.

In a typical AA zinc-carbon battery, the metal casing is made from solid zinc and forms the negative (-) terminal. The zinc casing covers all but the top of the battery, which is uncovered so that the positive (+) terminal, the carbon, is exposed. Chemical reactions in the battery cause a build-up of electrons at the negative terminal. If the positive and negative terminals are connected with a wire, the electrons repel each other all the way along the wire so that they begin to move from the negative terminal towards the positive terminal.

This movement of electrons is an electric current, which provides the device connected to the battery with energy. Eventually, though, the chemical reactions stop and no more electrons are released. When this happens, batteries run out of energy and become flat.

Big Question: Why Can Birds Sit on Pylons Without Getting Electrocuted? You’ve probably noticed that birds can sit on power lines without getting electric shocks. They can do this because they sit on a single line, which means they do not complete electrical circuits. This means that no current flows through them, so they do not get hurt.

But if they were to touch another line with a wing or a foot it would create a circuit – electricity would flow from one line to the other, electrocuting them.

The same thing would happen if someone on the ground made contact with one of these power cables – for example, a girl flying a kite. The kite touching the electrical cable would complete a circuit, giving the electricity a path down to earth. The current would flow from the power line, down through the kite string, into the girl’s hand, out through her foot and down into the ground.

Electricity can be very dangerous to living things if they become part of a circuit. Large currents as they pass through the body can cause the tissue to heat, causing internal burns. If a large-enough current passes through the chest it can cause the heart to stop.

Big Question: Why Does My Phone Always Need Charging? Many of the gadgets we use, such as tablet computers or mobile phones, are powered by batteries.

It's the chemical energy in the batteries that produces the electrical energy needed to power gadgets. Chemical reactions occur between metals and other chemicals in a battery, which creates an electric current.

Batteries don't last forever, however. When the chemicals inside are used up, the batteries become flat and stop working. When this happens, some batteries can be plugged into a source of electricity to start storing energy inside the batteries again. Not every battery can be recharged: some need to be safely disposed of once they have run out.

Imagine a battery is like a water tank at the top of a house. When the tank is full of water, the water can flow down the pipes. Eventually, all the water is used up. Recharging the battery is like refilling the tank with more water, ready to go again.

Scientist Stories: Edison vs. Tesla Following the discovery of electricity in the 1800s, Thomas Edison enjoyed a monopoly of the electricity market and earned vast sums of money distributing his direct current (DC) electricity.

However, there was a major drawback to direct current – it suffered huge power loss over distance, meaning the further you lived from the generator, the less electricity you would receive. At the time, there was no alternative supply and Edison's direct current electricity remained unchallenged.

Then, in 1887, renowned inventor Nikola Tesla devised a system for generating and distributing alternating current (AC). With alternating current, it was possible to supply useful amounts of power even at great distances from the generator. Tesla and his partner, George Westinghouse, commercialised alternating current and it was a major hit.

Standing to lose a lot of money, Edison began a smear campaign condemning alternating current as dangerous and potentially lethal. He spread rumours of fatal accidents caused by alternating current, demonstrating this by killing small animals with electric shocks.

In the 21st century, the alternating current remains the dominant form of electricity supply. More than 100 years since the war of the currents, it is Tesla, not Edison, whose electrical

legacy has prevailed.

You have now changed roles and have moved to being a writer. As part of your English pack, you will be writing a biography about Nikolas Tesla. The following sheets and activities will help you with this task.

Activity 5

Activity 6

In the section about lightning, static electricity was mentioned. This

is electricity that is naturally occurring around us. Have you ever

touched something and felt a little shock? In the summer, when I close my car door, I

sometimes get a small shock. This is all because of static electricity.

Be warned, the next three activities do not work as well if the weather is wet!

Magically separate pepper from salt.

Put some salt and pepper in a small dish.

Run a plastic comb through your hair several times.

Hold the comb over the dish and see what happens.

-the pepper should jump up; if you hold it too close, the salt will jump too

-the person who puts the comb through their hair (several times) must be the same person who holds the comb over the bowl.

Use a comb to bend water

Charge your comb up as in activity 7.

Run the tab so that there is a steady stream of water, not too fierce.

Hold the comb close to the water, but not touching it.

What happens to the stream of water? It should bend!

Jumping goop

Mix 1 tablespoon of cornflour with one tablespoon of oil.

Blow up a balloon and rub it on your hair.

Put the cornflour goop on a spoon and hold it close to the balloon. The goop with start to jump towards the balloon!

Why does this happen?

When you rub the balloon on your hair, electrons from the molecules in your

hair rub off onto the balloon. This gives the balloon a negative charge, and it is attracted to the

positive charges within the goop, specifically within the cornstarch.

Activity 7

Activity 8

Activity 9