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    General picture of science equipment

    Light up a bulb – and your scientific knowledge – with this illuminating test.

    Ingredients and equipment that you will need

    A simple circuit made from:
    – A low voltage battery
    – Copper wire
    – Small light bulb

    Method and further information

    Make a circuit with a low voltage battery and small light bulb. Break the circuit and hold the two wires apart in a jar of water. Until you touch them together, nothing happens.

    Now add some sugar. Again nothing.

    Now add some salt. In salty water the circuit is made even when the wires are apart. This shows that some solids, like salt, are made up of charged particles called ions.

    Be careful – you should ask an adult to help you with these experiments. Do your experiments in old yoghurt pots, jam jars or bottle tops. Don’t use cups or glasses in case someone thinks it’s a drink.