Here’s my silly demo. The balloon will rub against the head and then pull away with the “hair” standing on end. You might need to explain what it’s supposed to be. The next few slides show what is happening to the charges. These should run automatically.

- + - + + - - + - - + + + - + - - + - +

- - + - + + - - + - - + + + - + - + - +

- - + - + + - - + - + + + - + - + - +

- - + - + + - - + - + + + - + - + +

- - + - + + - - + - + + + + - + +

- - + - + + - - + - + + + + - + Re iterate that the head an balloon each started off with the same number of positive and negative charges but the rubbing moved charges onto the balloon and off the head. The balloon is now negatively charged and the head positively charged so that because opposites attract the hairs are attracted to the balloon And because like charges repel the airs are pushed apart from each other. +

Static electricity Static electricity is caused when certain materials are rubbed against each other. Electrons can be rubbed off one material and on to another. The material that has got extra electrons is now negatively charged The material which has lost electrons is positively charged.

Static electricity It is this imbalance of positive and negative charges that causes: Balloons to stick to walls. Your hair to stand on end when brush your hair on a dry day. And the electric shock you sometimes get from the door handle. Briefly show the pith ball electroscope. Both balls should be attracted to the charged rod but when they touch it they will be come charged with the same charge as the rod and then repel each other. This may not work well in humid weather which gives you a chance to explain that the weather affects what happens – one teacher was amazed when I pointed out that static sparks when you take a jumper off are much worse in dry weather,

Charge The electron is negatively charged. The proton is positively charged. The neutron has no charge, it is neutral.

Charge Most things have the same number of electrons and protons in them. They don’t have any overall charge. If this isn’t true interesting things can happen.

opposites attract, likes repel. How do charges behave? What do you know about magnets? 2 north poles will repel each other, but a north and a south put together will attract one another. opposites attract, likes repel. They should have covered magnets and be familiar with them. Put up the first sentence and then ask what will happen with the blue and red magnets.

How do charges behave? Exactly the same thing happens with charges. 2 positive charges put together will repel each other. Put a positive charge near a negative charge and they will attract each other. A charged object may even attract a neutral one.