Grade 5 (age 10-11)

grade 5 Separating Mixtures

A mixture is two or more substances mixed together, and because those substances have different properties, they can be separated again. If the grains are different sizes, filter paper sorts them; salt dissolved in water is recovered by evaporating the water; iron filings, which stick to a magnet, are picked out with a magnet. To choose a method, first work out what the mixed substances differ in. Switch the buttons above the picture and compare sand caught on filter paper, salt appearing as the water dries up, and only the iron filings rising to the magnet.

Three ways to separate

🔬 Filter paper

①Filter paper has tiny holes: water passes through but grains of sand are caught.

②So when you pour in muddy water, the sand stays on the paper and filtered water collects in the beaker below.

③This method uses a difference in grain size.

④Something spread very finely through water, like dissolved salt, is not caught by filter paper.

Choosing a method for each mixture

Comparing separation methods

Separation methods at a glance

Method	Property used	Example	What is mixed
Filter paper	Grain size	Sand + water	Undissolved solid + liquid
Evaporation	Only the water evaporates	Salt + water	Dissolved solid + liquid
Magnet	Sticks to a magnet	Iron filings + sand	Solid + solid
Settling	Grains sink to the bottom	Soil + water	Undissolved solid + liquid

💡 How to choose a method

①First, look at what is mixed with what.

②If an undissolved solid is mixed into a liquid, filter it or let it settle.

③If a solid is dissolved in water, evaporate the water.

④If something that sticks to a magnet is mixed in, use a magnet.

⑤Sometimes you use methods one after another. For salt mixed with sand, dissolve it in water and filter, then evaporate the filtered water to get the salt.

Summary

The idea behind separating

Different properties of the mixed substances → a suitable separation method

We use differences in grain size, in evaporating, in sticking to a magnet and in how fast things settle.

Main separation methods

Filter paper (grain size) / Evaporation (only water escapes) / Magnet (sticks to a magnet)

First find out which property the mixed substances differ in.

🎯 Key points

①A mixture is two or more substances mixed together.

②Filter paper uses a difference in grain size to take an undissolved solid out of a liquid.

③Evaporation uses the fact that only water escapes to get back a dissolved solid.

④A magnet uses the difference in sticking to a magnet to pick out things like iron filings.

⑤If you know how the mixed substances differ, you can separate the mixture.

Examples and Unit Test

Example 1

Which method should you use to get salt from salt water?

Salt is dissolved and spread very finely through the water, so filter paper cannot catch it.

When salt water is heated, the water turns to vapor and escapes, leaving only the salt.

▸ Evaporation (when the water evaporates, only the salt is left)

Press the evaporation button in the picture and you can see more salt grains appear as the water goes down.

Example 2

How can you separate a mixture of iron filings and sand?

Iron filings stick to a magnet, but sand does not.

Bring a magnet close and only the iron filings stick to it, apart from the sand.

▸ Pick out the iron filings with a magnet.

Wrap the magnet in paper or plastic first, and the filings are easy to take off afterwards.

Unit-test style

Which statement about separating mixtures is correct?

①Salt in salt water can be filtered out with filter paper.

②Iron filings and sand can be separated with a magnet.

③Evaporation uses a difference in grain size.

④Filter paper catches salt dissolved in water.

⑤Once mixed, a mixture can never be separated.

▸ ② Iron filings and sand can be separated with a magnet.

Iron filings stick to a magnet and sand does not, so a magnet can separate them.

Dissolved salt is not caught by filter paper (①, ④), evaporation uses the fact that only water escapes (③), and mixtures can be separated by their differences in properties (⑤).

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Last updated 2026-10-17