Contents
Key Stage 2
Meaning
A mixture is when two or more different substances are in the same place or are part of the same object.
About Mixtures
- Many materials are mixtures of different substances.
- Mixtures can usually be separated, but sometimes it is very difficult to do.
- Mixing is reversible change. Once two substances are mixed they can usually be separated again.
Examples
| Sea Water | Muddy Puddle | Beach |
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| Seawater is mixture of salt and water. | This puddle is a mixture of mud and water. | The beach is a mixture of sand and pebbles. |
Key Stage 3
Meaning
A mixture is a substance which contains more than one type of chemical.
About Mixtures
- A mixture can be made of different elements or it can be made of different compounds.
- The different chemicals in a mixture are not chemically bonded with each other.
- Mixtures can be separated without a chemical reaction.
Examples
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| A mixture of two different elements. | A mixture of two molecular elements. | A mixture of three different elements. |
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| A mixture of two compounds. | A mixture of a compound and an element. | A mixture of a compound and an element. |
Key Stage 4
Meaning
A mixture is a substance which contains more than one type of chemical.
About Mixtures
- Mixtures can be made of different elements, compounds or both.
- A mixture of metal elements is called an alloy.
- Mixtures can be separated by non-chemical processes.
Useful Mixtures
- In many cases a mixture can combine the useful properties of several chemicals in the mixture.
Some useful mixtures are:
- Surface Cleaner - Contains bleach to kill bacteria, a fragrance to give it a pleasant smell and a surfactant to emulsify oils.
- Paint - A dye to provide colour and a solvent for it to be spread over a surface.
- Heartburn Relief - A base to neutralise stomach acid, alginic acid to form a layer to protect the lining of the stomach and oesophagus.