Introduction to Electricity 7SCIENCE

Electricity brainstorm

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

Electric charges Usually atoms have the same number of protons and electrons so 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

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

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?