Like many scientists who lived 300 years ago, Benjamin Franklin worked on lots of different problems in science. But it wasn’t enough for him to just understand the science. With each discovery he made an invention: something to make people’s lives easier and safer. He made no money from his inventions, believing that they should be used freely by everyone.

What conducts electricity? This is a whole class activity which demonstrates how electricity moves in a circuit and how conductors and insulators work. Electricity is the flow of tiny charged particles called electrons. When electrons can move easily in a material, this material is called an electrical conductor. Electrons don't move so easily through an electrical insulator. A Class Circuit The class is going to be a circuit. In this circuit there will be a battery, a light bulb, and a gap in the circuit. The light bulb will not light up if the circuit is not complete. You will need... A class At least one balloon Some objects to be insulators and conductors You may also want: One balloon or ball (such as a tennis ball) per person How long will it take? About an hour depending on how long you want them to spend preparing for the activity and discussing it afterwards. What to do... Divide the class into groups. Assuming a class size of between 25 and 30 you will need... - Two students to be the battery - Two students to be the light bulb - Five sets of three students, to be conductors or insulators - The remainder to be the connecting wires 1. In their groups, the students need to look at their roles in the circuit. If they are in the battery group they are going to start the flow of electrons, so they need to start off by holding the balloon. If they are in a light bulb group then they will 'light up' when the electron (the balloon) reaches them. Ask them to hold the balloon high above their heads when it reaches them to show that they are 'lit'. If they are one of the connecting wires then they will always conduct electricity and will keep the electron flowing from one area to another. If they are in one of the five object groups they will be given an object. Ask them to decide on whether this object is a conductor or an insulator.  This is what they are going to be when you are in the circuit. Objects could be: Conductors Metal fork Set of keys Paper clip Insulators Plastic

spoon Pencil Rolled up newspa

per 2. When the groups are ready they need to assemble themselves into the circuit, according to the diagram below. One of the five object groups will form part of the circuit, with the battery, light bulb and connecting wires. The other sets of insulators / conductors can take their turns later on. 3. Give a balloon to the battery and tell them that this is an electron flowing in the circuit. They now need to pass the balloon around in the circuit to their right (anticlockwise) until they hit the gap which has been filled by one of the object groups. If that group is an insulator then ask them to keep their hands behind their backs during the game. They are not allowed to use their hands at all.  Once the balloon has come to a stop the insulator group need to leave the circuit and be replaced by the next group.  Return the balloon to the battery. 4. If the gap has been filled by a conductor the balloon passes on and when it reaches the lamp the students can lift the balloon above their h

eads to show the lamp is on! 5. Change groups so all the groups have had a chance to fill the gap. What's happening? An insulator in the gap stops the flow of electrons and the lamp does not light. If there is a conductor, the balloon is passed on and the lamp lights. In reality, the electrons do not actually stop at the insulator. A closer analogy to how electricity actually flows through the wire is to give everyone a balloon or a ball. Ask them to pass it on at the same ti

me (assuming you have a conductor in the gap). This is a little tricky with balloons so you may want to try this out with something that the students can hold in one hand, such as tennis balls. They need to pass the balls with a steady motion so no one is left without a ball, or holding two balls for too long. This shows that the effect of electricity moves at the speed of light while the electrons themselves actually travel much more slowly. You can even take it further and ask the students forming an insulator if they could try and move the balloon or ball on without using their hands. This would be analogous to fact that not all insulators completely stop the flow of electrons. Answers for wordsearch: Conductor Insulator Nail Shoe Spanner Glass Paper clip Jumper Gold ring Plastic bag Wire Pencil Royal Society links: Read Franklin's letter about electrocuting a turkey here.

Curriculum links:

Science: Working scientifically
Lower Key Stage 2
Year 4 Electricity
Upper Key Stage 2 Year 6 Electricity
Literacy: Reading - Comprehension
PE: Develop flexibility, strenghth, technique, control and balance

 

Scottish Curriculum:

Science SCN 2-08a Forces, electricity and waves - Forces
SCN 2-09a

Forces, electricity and waves - Electricity

Using a range of electrical components to help to make a variety of circuits for differing purposes. Represent circuits using sympols and describing the transfer of energy around the circuit.

SCN 2-10a

Forces, electricity and waves - Electricity

To begin to understand how batteries work, helping to build simple chemical cells using readily-available materials which can be used to make an appliance work.

Social Studies SOC 2-06a People, past events and societies


Lightning strike

Read the background to this activity.

Go to the wordsearch. Go to the activity.

Benjamin Franklin is most famous for studying electricity. In the 18th century scientists were just beginning to understand electricity. A few years before Benjamin Franklin's experiments, scientists had found that electricity could flow through conductors, that insulators stopped the flow of electricity and that electricity would flow around a circuit. Benjamin Franklin proved that lightning was electricity by flying a kite in a thunderstorm. This is incredibly dangerous and he was lucky enough not to be hit by lightning or this would have been his last discovery! As with so much of Benjamin Franklin's work, he found something useful to do with his discovery. In this case he invented the lightning rod, a long pointed metal rod that is attached to the top of buildings. Lightning rods have a conducting wire which guides the electricity from a lightning strike into the ground, rather than through the building which helps prevent any damage from happening. Franklin also conducted some more unusual experiments with electricity. He once wrote a letter that described how much electrical charge it would take to electrocute a turkey! Back in Franklin's time there weren't as many rules about experimenting on animals, although this may have been useful around Christmas time!   In this word search, can you find five everyday items which are electrical conductors, and five which are electrical insulators? Download the wordsearch for printing.

A Class Circuit How does electricity flow through conductors?  You can show how electricity works with a few people and a balloon! Electricity is the flow of tiny charged particles called electrons. When electrons can move easily in a material, this material is called an electrical conductor. Electrons don't move so easily through an electrical insulator. Download the pdf worksheet here.

You will need...

Your classmates (parts of the circuit) At least one balloon (electron)

What to do...

1.  You will be divided into groups...

- Two people will be the battery

- Two people will be the light bulb - Five sets of three people will be objects, either conductors or insulators - The remainder of the class will be the connecting wires 2. Deciding roles.... If you are in a battery group. You are going to start the flow of electrons, so you need to start off by holding the balloon. If you are in a light bulb group. You will 'light up' when the electron (the balloon) reaches you. You will need to hold the balloon high above your heads when it reaches you to show that you are 'lit'. If you are in an object group. You will be given an object, such as a pencil, metal fork or plastic spoon. You will need to work out whether your object is a conductor or an insulator.  This is what you are going to be when you are in the circuit. If you are one of the connecting wires. You will be the important part of the circuit that keeps the electron flowing from one area to another. 3.  In your groups have a look at the job you will do in the circuit.  Will you conduct electricity? 4. When you are ready you will need to form the circuit.  Start by having the battery, lamp and only one of the object groups in a circle.  Make sure the lamp is to the left of the battery.  The connecting wires now need to fill the gaps between the battery, lamp and object. Move the circle out so there is room for everyone. 5.  The battery group start off by holding the balloon, and they need to pass the balloon around to their right.  This is an electron flowing in your circuit! 6.  When it gets to the object group, you will need to say whether your object is a conductor or an insulator.  If it is an insulator then you cannot pass on the balloon when it reaches you, the balloon stops and the lamp does not light. 7. If the gap has been filled by one of the conductor groups the balloon passes on and when it reaches the lamp the lamp group can lift the balloon above their heads to show the lamp is on! 6. Once the balloon has reached the battery again you have shown your circuit works.  Now fill the gap with another object and start again.

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Benjamin Franklin is most famous for studying electricity. In the 18th century scientists were just beginning to understand electricity. A few years before Benjamin Franklin's experiments, scientists had found that electricity could flow through conductors, that insulators stopped the flow of electricity, and that electricity would flow around a circuit. Benjamin Franklin proved that lightning was electricity by flying a kite in a thunderstorm. This is enormously dangerous. Either he had a way of insulating himself or he was lucky enough not to be hit by lightning or this would have been his last discovery. <!--[if !supportAnnotations]-->[AM1]<!--[endif]-->   As with so much of Benjamin Franklin's work, he found something useful to do with his discovery. In this case he invented the lightning rod, a long pointed metal rod that attached to the top of buildings. Lightning rods have a conducting<!--[if !supportAnnotations]-->[AM2]<!--[endif]--> wire which guides the electricity from a lightning strike into the ground, rather than through the building<!--[if !supportAnnotations]-->[e3]<!--[endif]--> .   In this word search, can you find five everyday items which are electrical conductors, and five which are electrical insulators? <!--[if !supportAnnotations]--> <!--[endif]--> <!--[if !supportAnnotations]--> <!--[endif]--> <!--[if !supportAnnotations]--><!--[endif]--> <!--[if !supportAnnotations]-->[AM1]<!--[endif]-->Any picture of lightning is good - this one is from...   http://commons.wikimedia.org/wiki/File:Phatman_-_Lightning_on_the_Columbia_River_(by-sa).jpg   <!--[if !supportAnnotations]--> <!--[endif]--> <!--[if !supportAnnotations]--> <!--[endif]--> <!--[if !supportAnnotations]--><!--[endif]--> <!--[if !supportAnnotations]-->[AM2]<!--[endif]-->Any picture of lightning hitting a building   http://commons.wikimedia.org/wiki/File:Lightning_striking_the_Eiffel_Tower_-_NOAA.jpg <!--[if !supportAnnotations]--> <!--[endif]--> <!--[if !supportAnnotations]--> <!--[endif]--> <!--[if !supportAnnotations]--><!--[endif]--> <!--[if !supportAnnotations]-->[e3]<!--[endif]-->Could we get a bit of information about the activity in here? Describe it so that children can understand it and then all the detail about setting it up on the teachers' page? <!--[if !supportAnnotations]--> <!--[endif]-->