Puddles on the playground
What happens to puddles on the playground?
What do you understand about changing states? How could this knowledge help you to separate water from salt?
Adult support needed for heating
You could try heating a mixture of salt and water in a small metal tray over a night light candle. What happens to the water? What would happen to the salt?
So how could the sun separate water from salt using the sun?
How could you test this?
- You could place a few centimetres of salty water into a mixing bowl then place a small beaker in the centre of the beaker.
- Stretch some clingfilm over the opening of the bowl and place a weight in the middle above the small beaker (making a dip in the clingfilm above the small beaker).
- Then you could place the equipment in the sun or heat it with a lamp.
- What happens?
How will you record your findings?
Will you draw diagrams, write a report or choose a different way?