Static Electricity Lab Part 1

Transcription

1 Static Electricity Lab Part 1 Objective: Understand how electric charges interact and how static electricity builds up and transfers. Materials: balloons unflavored gelatin flat plate ping-pong ball Procedure: Stuck-Up Balloon bubble solution & wand clear plastic container aluminum foil rice cereal piece of wool Gelatin Towers 1. Blow up a balloon and tire the end so that the balloon stays inflated. 2. Without doing anything else, hold the balloon against the wall and see if it will stick. What happens? Why? 3. Briskly rub the balloon across your hair (works best if your hair is clean and dry). Hold the balloon against the wall and see if it will stick. Does the balloon stay? Can you explain what happened? 1. Spread some unflavored gelatin powder evenly onto a flat plate. 2. Blow up a balloon, tie it, and charge it as you did in parts A and B. Touch the charged area of the balloon to the dish of gelatin. 3. Gently raise the balloon straight up. What happens? Why? Dancing Ping-Pong Ball 1. Charge a balloon as in parts A, B, C, or D. Place a ping-pong ball on a level surface such as a tabletop or smooth, bare floor. 2. Bring the charged balloon near the ball. What happens? Why? Fun with Bubbles 1. Blow a bubble, and then catch it on your bubble blower. 2. Move a charged balloon around near the bubble. What happens? 3. Blow the bubble into the air, and then bring the charged balloon the bubble. Can you get the bubble to follow your balloon around in the air? What happens? Why? Snap, Crackle, Pop, and Hop! 1. Place a thin layer rice cereal on a sheet of aluminum foil.

2 2. Then put a clear plastic container (about 1-2 inches deep) upside down over the cereal. 3. Vigorously rub the upper outside surface of the container (the bottom of the container, since it s upside down) with a piece of wool. What happens to the cereal underneath the container? Why?

3 Static Electricity Lab Part 2 Objective: Understand how electric charges interact and how static electricity builds up and transfers. Materials: balloons lightweight string salt & pepper lightweight paper piece of wool water faucet Procedure: Dancing Balloon Dancing Water Dancing Paper Salt and Pepper 1. Blow up 2 balloons and tie each one closed. Tie a long thread or string onto the end of each balloon. 2. Give each balloon a static charge by rubbing it with your hair as in part A. 3. Hold each balloon by the end of the thread and try to bring the balloons close to each other. What happens? Why? 1. Rub an inflated balloon with your hair to charge the balloon as you did in parts A, B, and C. 2. Turn on a faucet so a thin, steady stream of water comes out. 3. Bring the balloon near the stream of water. What do you see happening? Can you explain why? 1. Place the pieces of paper on the table. 2. Charge a balloon as in part E. 3. Bring the charged balloon near the pieces of paper. What happens? Why? 1. Sprinkle some salt onto a plate or tabletop. 2. Bring a charged balloon near the salt. What happens? Why? 3. Then, sprinkle some pepper onto the table so that you have a mixture of salt and pepper. How do you think you might be able to separate the salt from the pepper? 4. Bring your charged balloon near the pile of salt and pepper particles. What happens? Which pieces were picked up more easily? Is this a good way to separate salt and pepper if they accidentally get mixed?

4 Static Electricity Answer Sheet For each mini-lab, make sure you explain what happened and why what were the objects charges and how did that cause it to react the way it did. Part 1 Describe what you saw and why you think it happened. Stuck Up Balloon Gelatin Towers Dancing Ping- Pong Ball Snap, Crackle, Pop, and Hop Fun with Bubbles Part 2 Dancing Balloon Describe what you saw and why you think it happened. Dancing Water Dancing Paper Salt and Pepper

5 Static Electricity Questions 1. What are the three subatomic particles and what are their charges? 2. What will happen if two positively charged objects come into contact? 3. Why is there no overall charge in a neutral object? 4. How can an object become charged? 5. If an object gains electrons, what will its overall charge be? 6. If an object loses electrons, what will its overall charge be?

6 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. 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.