Current Electricity

he first battery (or cell) was discovered by Luigi Galvani. He was dissecting a frog at the time. He happened to be using two dissecting tools each of different metals. He touched a nerve and the dead frog's leg twitched! He had accidentally produced an electric current. This lead to the development of what we now call the battery. To be pedantic, the correct name is a cell and a battery is really the name given to a collection of several cells joined together to produce a higher voltage.
A cell can be made from a lemon:

It requires a very sensitive ammeter to detect this current. This will not produce a sufficient current or voltage to light a bulb or, in fact, do anything very useful!

Making a bulb lightIt can be discovered that the following criteria need to be met:

A complete circuit with no gaps Both ends of the battery must be connected within the loop The circuit must be joined by conductors

N.B. It is far more useful for children to discover how to make a bulb light for themselves, rather than be shown how to do it.
ModelsThe flow of electricity can be compared to a flow of water through a pipe.

• The water pump can be compared to the battery.
• The pipes can be compared to the leads.
• The thin pipe can be compared to a bulb.

It is, of course, important to realise the limitations of this model, e.g. nothing leaks out of the wire if it is cut!
An electric current is a flow of electrons. The battery gives the electrons energy which results in this current. But what are electrons?