🧪 How Do We Separate Mixtures?

Oh dear! Rice, lentils and paper clips have all got mixed up in one bowl. How can we get them apart again? Let’s find out together!

When several materials are put together, we get a mixture. Rice, lentils and paper clips mix, but each one keeps its own properties. A material with only one kind of stuff in it is a pure substance, for example sugar. And we can separate the things in a mixture again.

The secret of separating a mixture is to look at how the materials are different. If the bits are different sizes, use sieving. If there is iron in it, use a magnet. If a solid is mixed with a liquid, use filtering.

Sieving: We shake the mixture in a sieve. Small bits, like sand, fall through the holes. Big bits, like pebbles, stay in the sieve.

Separating with a magnet: A magnet pulls things made of iron. Paper clips are made of steel, which has iron in it, so they stick to the magnet. The rice stays where it is.

Filtering: When a solid is mixed with a liquid, we use filter paper. As muddy water goes through the paper, the sand and soil stay on the paper and the water drips down.

There is one more way: evaporation. Salt dissolves in water, so we cannot see it, and it goes straight through a filter. But if the water evaporates, it goes into the air and the salt is left behind. We do it in the sunshine, or with a grown-up’s help.

Now imagine you work in a plant. A mixture arrives and you pick the right machine. First, look at how the materials are different.

To sum up: the materials in a mixture keep their own properties. Different sizes: sieving. Iron in it: a magnet. A solid in a liquid: filtering. In salt water, the salt is left when the water evaporates. Now try it in Mixture Plant!