Static Electricity and Magnetism: Understanding charges, attraction, and repulsion

1. Do NOW (on p 34): Discuss with your elbow buddy - Does this happen to you? • does your hair stand up when you take off your hat? • do you sometimes get a shock when you touch a friend? • Why does that happen?

2. Do now: energy

3. Static energy

4. What is Static Electricity? Everything we see is made up of tiny little parts called atoms. The atoms are made of even smaller parts. These are called protons, electrons and neutrons. They are very different from each other in many ways. One way they are different is their "charge." Protons have a positive (+) charge. Electrons have a negative (-) charge. Neutrons have no charge. Usually, atoms have the same number of electrons and protons. Then the atom has no charge, it is "neutral." But if you rub things together, electrons can move from one atom to another. Some atoms get extra electrons. They have a negative charge. Other atoms lose electrons. They have a positive charge. When charges are separated like this, it is called static electricity.

5. If two things have different charges, they attract, or pull towards each other. If two things have the same charge, they repel, or push away from each other. • So, why does your hair stand up after you take your hat off? When you pull your hat off, it rubs against your hair. Electrons move from your hair to the hat. Now each of the hairs has the same positive charge. Things with the same charge repel each other. So the hairs try to move away from each other. The farthest they can get is to stand up and away from all the other hairs. If you walk across a carpet, electrons move from the rug to you. Now you have extra electrons. Touch a door knob and ZAP! The electrons move from you to the knob. You get a shock.

6. Do NOW: Use the eclicker to answer true or false In A a charged rod is repelling a copper ball. In B two charged balls are attracted. A. B. Click in A =True; B= false ____ 1. In A the rod is positively charged ____ 2. In B, ball 1 has a negative charge ____ 3. In B, the positive charged rod will be attracted to Ball 1 review p 27-29 + + ? ? ? 1 2

7. Static lightbulb

8. Static electricity • Static electricity is a buildup of charge on an object.

9. Static Electricity • Like charges repel – unlike charges attract • Positive (+) and Negative (-) charges attract or pull together. • Positive (+) and Positive (+) charges repel or push apart. • Negative (-) and Negative (-) charges repel or push apart.

10. Van de Graaff Generator: • When the motor is turned on, the lower roller (charger) begins turning the belt. Since the belt is made of rubber and the lower roller is covered in silicon tape, the lower roller begins to build a negative charge and the belt builds a positive charge. You can understand why this charge imbalance occurs by looking at the triboelectric series: Silicon is more negative than rubber; therefore, the lower roller is capturing electrons from the belt as it passes over the roller.

11. http://amasci.com/emotor/vdgdemo.html Some atoms hold on to their electrons more tightly than others do. Positive items in the series are at the top, and negative items are at the bottom: • Human hands (usually too moist, though) Very positive • Rabbit Fur • Glass • Human hair • Nylon • Wool

12. Some atoms hold on to their electrons more tightly than others do. Positive items in the series are at the top, and negative items are at the bottom: from more positive to less positive. • Human hands (usually too moist, though) Very positive • Rabbit Fur • Glass • Human hair • Nylon • Wool • Fur • Lead • Silk • Aluminum • Paper • Cotton • Steel Neutral • Wood • Amber • Hard rubber • Nickel, Copper • Brass, Silver • Gold, Platinum • Polyester • Styrene (Styrofoam) • Saran Wrap • Polyurethane • Polyethylene (like Scotch Tape) • Polypropylene • Vinyl (PVC) • Silicon • Teflon Very negative

13. Exit ticket • On p. 29:How did the demonstration of the VDG generator help you understand static electricity and the way charge transfers? Give 2 details from your reading and the demo. • Why did Morel’s hair go up? Explain what happened. • Use some of the terms: electrons, charge, positive, negative, neutral, like, unlike, attract, repel • Continue on p 33.

14. Do Now: • What part of the magnet attracts the most paper clips? 1. With your elbow buddy, use the bar magnet OR the horseshoe magnet. Take turns with others at your table. 2. See if you can make a paper clip stick to different parts of each magnet. 3. Draw a diagram on p 33 of your energy packet showing the number and location of paper clips on each magnet.

15. Magnetism • Magnets have 2 poles, North and South • Opposite poles (North and South) attract • Like poles (South and South) (North and North) repel • The area around a magnet where the force is strongest is called the magnetic field.

18. Reflection: • Look back at the activity at each station and reflect on what each station showed you about magnetic force, or the magnetic field. • On the inside cover of your magnetic notebook, write at least 1 sentence about what each station showed about magnetism. You may want to use diagrams. Terms to use: attract, repel, poles, force, magnetic field lines

19. Do Now: • Using two wires, one battery and a bulb, can you get the bulb to light up? • Draw it in your Energy 2 packet p 2.

20. Electricity • Electricity is a flow of electrons • An electric circuit is a pathway that allows the flow of electrons. • An electric circuit has 3 parts: • Power/Energy source • 2. Switch • 3. Resistor - Objects that require an electrical current to work (ex. light bulbs, fan, bell).

21. Do Now: • Using three wires, one battery, a bulb, and a switch, can you get the bulb to light up?

22. Open and Closed Circuits • An open circuit does not allow the flow of electricity (lights turned off) • A closed circuit allows the flow of electricity (lights turned on).

23. DO NOW: Using symbols from yesterday (page 3) • Draw an open circuit with 6 resistors. • Draw a closed circuit with 4 resistors and 2 power sources. • Draw a closed circuit with 5 resistors.

24. 2 Types of Circuits • Series circuits (Christmas lights) are all wired together to the power source. If one bulb goes out, they all go out. • Parallel circuits (store signs) are wired separately to the power source. If one bulb goes out, the others stay on.

26. What happens if one bulb goes out? Series Parallel Why do you think your appliances at home are connected in parallel circuits?

27. Conductors • Metals are good conductors of electricity (for example: wires) • They CONDUCT, or pass along, electricity • Plastic is a poor conductor, or insulator, of electricity (covers the wires). • INSULATORS do not conduct, or pass along, electricity • BBC website http://www.bbc.co.uk/schools/scienceclips/ages/8_9/circuits_conductors_whatnext.shtml

28. Reflection Journal questions • Why do you think electrical wires are made of metal? • Why are electrical wires covered with plastic? • How are electrons related to electricity? (remember our game?) • Thinking question: How could you use a circuit to test if something passed along electricity?

29. Do Now: • Work with your elbow buddy. • Using the materials at your desk, and your knowledge of science, make the paperclips attract to the nail.

30. Do Now • Write 2 sentences about what you learned about yesterday. • Use the following terms: Conductor insulator electricity electrons tightly-bound • You have 3 minutes. • ________________________________________________________________________________________________________________________________________________________________________________

31. Electromagnets • Brainpop • brainpop/electromagnetic induction/