3. What is electricity? Electricity is matter and we know all matter is made of: atoms Atoms are made of even smaller particles called electrons and protons These have an electric charge Electrons = negative Protons = positive
4. Electric charges Usually atoms have the same number of protons and electronsso the positive and negative charges are balanced Sometimes atoms gain or lose an electron Gain = negative (adding negative!) Lose = positive (taking away negative!) These electrons can move between objects and build up Ex. Rubbing a balloon on your hair Building up of electric charge is called static charge
5. Electric forces Charged objects have an electric force Electric force can be: Attractive Repulsive Rule: objects with the same type of charge repel each other and those with unlike charges attract ex. + and + = repel ex. + and - = attract
6. Insulators and Conductors Materials that don’t allow electrons to move easily from one surface to another is called an insulator Ex. Plastic, wood, rubber Materials that allow electrons to move through them easily are called conductors Ex. Metal wires: copper, silver, iron Why are electrical wires covered in plastic/rubber coating? Do you think your body is an insulator or conductor?