Water Cycle In A Bowl
What's this Science Bite about?
Make your very own mini water cycle. The heat from the sun will cause the water in the bowl to evaporate. This water vapour will condense to form water droplets before falling down into the container.
What you'll need
- A large, clear bowl
- A small container
- Large rubber band
- A small pebble or weight
- Table salt (optional)
- Some sunshine!
How to do the experiment
Pour a small amount of water into the bowl.
Place the small container in the centre of the bowl.
Cover the bowl with clingfilm and secure with the rubber band.
Put the pebble or weight in the centre of the clingfilm, over the small container.
Place the experiment on a windowsill or somewhere that is well lit by the sun.
After 2-3 hours check on the experiment.
Find out more...
The water in the bowl will be heated by the sun. This rise in temperature will cause the water to start evaporating. When water evaporates it turns into a gas, known as water vapour. This is exactly what happens to the water in oceans and lakes.
Water vapour is invisible and likes to rise up to the sky. However, it will be stopped by the clingfilm. The clingfilm will also cool the water vapour and turn it back into liquid water droplets. The process of water vapour cooling to become liquid water is called condensation.
This process of condensation also happens to water evaporated from oceans and lakes. Water vapour will rise up to the sky, but will eventually start to cool down as it rises higher and higher. Like in our experiment, the water vapour will then condense into liquid water droplets. When enough water vapour has condensed into water droplets clouds will start to form.
When enough water has condensed on the clingfilm it will start to roll down the slope created by the weight/pebble and fall back into the small container. When water droplets become too heavy and fall back to the ground we call this precipitation. This is usually identified as rain, but snow and hail are also forms of precipitation.
Before pouring it into the bowl, add a small amount of salt to your water and stir it to make salt water. Is the water collected in the small container also salty?
Processes of the Planet
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