Essential Questions: How does electricity work, and why does it form? How can electricity be useful?

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2 Essential Questions: How does electricity work, and why does it form? How can electricity be useful?

3 Appliances Lamps Computers Refrigerators Microwaves Flashlights Cell phones Video games

4 All matter is made up of tiny particles called atoms. Each atom is made of three smaller particles. They are: Protons (+) found in the nucleus of the atom Neutrons (N) found in the nucleus of the atom Electrons (-) found floating around the nucleus in an electron cloud

5 A neutron walks into McDonald s and asks, How much for a cup of coke? The cashier replied, For you, no charge.

6 Most objects are neutral they have the same number of protons and electrons. However, because electrons are floating around in electron clouds, they can sometimes catch or be transferred onto other objects. When this happens, objects will become either positively or negatively charged. This flow of charged particles is called electricity.

7 An object that is positively charged has more protons, and it is negatively charged if it has more electrons. Objects with opposite charges attract (pull towards) each other. Objects with the same charges repel (push away from) each other.

8 When electrical charges build up on the surface of an object and then suddenly flow to a new object, static electricity occurs. See B: After rubbing, there are more negative charges now on the shoe. The shoe is now negatively charged, and the carpet is positively charged.

9 What causes you to be shocked when you rub your feet across carpet? An electrical discharge is the passing of an electric current through the air from a negatively charged object to a positively charge object. This is what causes lightning!

10 Friction is what causes the electrons to stick to something new. What about in life? Has your negative attitude ever rubbed off on to someone? Ever heard the phrase One bad apple can ruin the entire bunch? Philippians 2:4-5 (NLT)~ 4 Don t look out only for your own interests, but take an interest in others, too. 5 You must have the same attitude that Christ Jesus had.

11 What happens to your hair when you rub the balloon on your head? WHY? What happens to the balloon after your rub it on your pants and then put it on the wall? WHY? What happens if you put a charged balloon near another charged balloon? WHY?

12 What happens when you put a charged balloon near a flowing stream of water? WHY?

13 The van de Graf generator (large silver ball) deposits electrons on the ball. When a person places his/her hand on the ball and the machine is turned on, electrons are transferred to and collected on the person touching the silver ball. Why do you think this machine affects the hair of the children in the picture?

14 Essential Questions: How does electricity work, and why does it form? How can electricity be useful?

15 Unlike static electricity, which is fun but mostly useless, current electricity is the electricity that we use to power up electrical devices. Current electricity is the flow of negative charges (electrons) around a circuit. A circuit is a continuous, unbroken path through which electricity can flow. (This is usually something like a metal wire.) It works like a rollercoaster or one-way circle.

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17 Circuits are either open (broken) or closed (complete). To have a complete circuit, the electricity must be able to flow without a break in the circuit. (Like a one-way circle.) Let s try it!! Your battery will be your current electricity source, and you will need to find a way to make your light bulb light up. It will work if you complete the circuit. Remember! The circuit must be CLOSED.

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20 Circuits can be opened or closed by using switches. Without a switch, there would be no way to stop the flow of electrons. A switch is a conductor that can either bridge or not bridge the gap in a circuit. The on feature completes (closes) the circuit, and the off feature breaks (opens) the circuit. Let s make an on/off switch!

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24 Essential Questions: How does electricity work, and why does it form? How can electricity be useful?

25 There are two types of circuits: Series Circuits Parallel Circuits Circuits run along electric paths, like mazes, and will flow as long as the circuit is complete. More than one device can run on a single circuit, but the circuit must be complete.

26 If there is only one path for the electricity to follow, then it is a series circuit. A series circuit that has a break anywhere in the circuit will not work. (Think of old Christmas lights! Sometimes some of them will not work at all if one bulb goes out. This is because many Christmas light lines work on series circuits.)

27 If there are multiple paths for electricity to follow, then it is a parallel circuit. A parallel circuit can still work even if there is a break in the circuit, that is because it is complete somewhere else.

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29 Essential Questions: How does electricity work, and why does it form? How can electricity be useful?

30 A conductor is a material that allows electricity to flow through it easily. An insulator is a material that does not allow electricity to flow through it. A resistor reduces the flow of electrons. Resistors usually get hot and light up (without burning up) because of the friction created i.e. the filament in a light bulb! Let s find out which materials conduct electricity best, and which would be good insulators!