Year 2 · Science · Chemical sciences
Mixing materials
Children mix materials such as salt, sand, oil and water, observe what happens, and notice that some mixtures can be separated again.
Awaiting educator review. This material was drafted by our content team with AI assistance and is waiting for review by a qualified educator. Please check it suits your child before using it. Created 10 October 2026.
Learning goals
Learners will
- Mix everyday materials and describe what happens.
- Notice that some materials dissolve in water and some do not.
- Separate a simple mixture.
Success looks like
- I can predict what will happen when I mix two materials.
- I can say whether a material dissolved in water.
- I can separate sand from water using a strainer and paper towel.
The big idea
When we put two or more materials together, we make a mixture. Fruit salad, trail mix and muddy water are all mixtures.
Some solids dissolve in water. When you stir salt or sugar into water, the grains seem to disappear. They are still there, though: the water tastes salty or sweet.
Some solids do not dissolve. Sand sinks to the bottom of the cup and you can still see it.
Some liquids do not mix with water. Cooking oil floats on top of water in a layer.
We can separate some mixtures. Pouring sandy water through a strainer lined with paper towel catches the sand and lets the water through.
Cooks, builders and farmers mix materials every day. Concrete is a mixture of cement, sand, gravel and water.
Worked examples
Salt in water
What happens when you stir a teaspoon of salt into a cup of water?
- Predict: will the salt disappear or stay at the bottom?
- Add the salt and stir for one minute.
- Look: the water looks clear again.
- The salt has dissolved, but it is still in the water.
Answer: The salt dissolves into the water.
Separating sand
How can you get the sand back out of sandy water?
- Line a strainer with paper towel and hold it over an empty cup.
- Slowly pour the sandy water in.
- Watch the water drip through.
- The sand stays on the paper towel.
Answer: Pour it through paper towel; the sand is caught and the water runs through.
Practice check
Have a go, then check your answers. Each answer comes with an explanation.
Answer guide for parents
Which material dissolves in water?
Sugar — Sugar dissolves when stirred into water.
What happens when you pour cooking oil into water?
It floats on top — Oil does not mix with water; it floats as a layer on top.
Which of these is a mixture?
Fruit salad — Fruit salad is many foods put together, so it is a mixture.
How can you separate sand from water?
Pour it through paper towel — The paper towel catches the sand and lets water through.
After salt dissolves, how could you tell it is still in the water (with an adult's OK)?
The water tastes salty — The salt is still there, so a tiny taste is salty.
When sugar seems to disappear in water, we say it d________.
dissolves — Sugar dissolves in water.
Does sand dissolve in water? Answer yes or no.
no — Sand does not dissolve; it sinks to the bottom.
Two or more materials put together make a m______.
mixture — Materials put together make a mixture.
Watch out for
- Children often think dissolved salt or sugar has gone. It is still there, in pieces too small to see.
- Some think 'melting' and 'dissolving' are the same. Melting needs heat (ice to water); dissolving is mixing into a liquid.
- Some think all liquids mix with water. Oil does not.
Tips for parents
- Label each cup before mixing so results are easy to compare.
- Only allow tasting of food-safe mixtures (salt water or sugar water) and only with your permission.
- Safety: wipe up spills straight away so floors are not slippery, and never mix cleaning products.
Go further
- Try dissolving sugar in warm water and cold water (adult pours the warm water). Which dissolves faster?
- Leave a saucer of salty water in a sunny spot for a few days and look for salt crystals.
- Make a muddy-water filter using a cut plastic bottle, cotton wool, sand and gravel.