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Student Lab Sheet This lesson is an introduction to the interesting concept of electricity. We are beginning with static electricity which means electrical charges that are not moving. Please follow the instructions on your lab sheet to carry out each experiment. Materials provided for you are laid out on your table. Activity 1. 1. Put some salt a in the paper plate provided. Take a plastic ruler and place it over the pile of salt and pepper. What do you observe? __________________________________________________ 2. Now rub the ruler with the cloth or wool provided for about 10 seconds. Again, place the ruler over the pile of salt and pepper. What do observe? _____________________________________________________ Activity 2 1. Blow some air into some balloons and try to stick the balloons to the wall. What do you observe? _____________________________________________________ 2. Now rub the balloons on your head (if there is hair), or against a piece of cloth. Now try to stick against the wall. What do you observe? __________________________________________________ Students share their their results, one group at a time. Class Journal Entry Questions: 1. Why do you think the ruler and the salt and pepper pile behaved the way they did? 2. What does rubbing the balloon and ruler do that causes there to be a reaction? Write your answers in your journal and turn it in at end of class. Brief Overview Matter is made up of small particles called protons and electrons. Every object is electrically neutral until some activity like rubbing causes them to have extra or less electrons. When this happens we say that the object is "charged". Some materials are more prone to to loosing electrons faster than others. Such substances are called insulators, and some that cannot be charged up like copper are called conductors. Excess electrons are created on the surface of the balloon when rubbed against hair, these electrons "jump" at the wall so to speak when the balloon is brought near the wall. We say that there is an attraction between the wall and the balloon. You may need to introduce the properties of some materials, like fur, to easily create static electricity. Application of concept: Your new assignment is to use a balloon to pick up the pieces of paper you are provided. Carry out the experiment and then describe in your own words how you did it and what your results are. Enter in your journal what causes electricity. Also enter what you learned today. |