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What Happens When You Mix Things

What you’ll find out

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No sign-up and no real names. In the lesson you check your understanding as you read, run the experiment yourself, and practise until it sticks.

Some things disappear into water

Stir sugar into a glass of water and it seems to vanish. It has not gone anywhere — taste the water and it is sweet. We say the sugar dissolved. Now try sand. The sand sinks to the bottom and stays there. Sand does not dissolve.

Getting things back apart

You can get the sand back easily — just pour everything through a sieve and the sand stays behind. You can get salt back too, but a different way. Leave the salty water in a warm place. The water goes into the air and the salt is left behind.

Curriculum links: NGSS 2-PS1-4