New
New
Lesson 7 of 20
Lesson 7 of 20
New
New
Soluble and insoluble
I can compare materials based on whether they are soluble or not.
Lesson details
Key learning points
- Some solids dissolve in liquids to form a solution.
- Solutions are always clear, though they may or may not have a colour.
- When a solid dissolves, it is broken down to become so tiny we can no longer see it, but it is still there.
- A substance that dissolves is said to be soluble.
- A substance that does not dissolve is said to be insoluble.
Keywords
Dissolve - If a solid dissolves in a liquid, it mixes so completely with the liquid that it cannot be seen.
Solid - A solid keeps its shape and volume.
Liquid - A liquid can flow and take the shape of the bottom of its container.
Soluble - A material that will dissolve is soluble.
Insoluble - A material that will not dissolve is insoluble.
Common misconception
Dissolving is the same as melting.
Teaching slides explain the difference between melting and dissolving.
Encourage pupils to use the word “dissolve” rather than “disappear” or “melted”. This lesson contains a diagnostic question on slide 10 - see additional materials for further guidance.
Teacher tip
Equipment
See additional materials: beakers, water, teaspoons, a range of households solids e.g. sugar, salt, flour etc.
Content guidance
- Risk assessment required - equipment
Supervision
Adult supervision required
Licence
This content is © Oak National Academy Limited (2026), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).
Lesson video
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Prior knowledge starter quiz
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6 Questions
Q1.Which of these is a gas at room temperature?
Which of these is a gas at room temperature?
brick
water
Q2.Which of these materials are metals?
Which of these materials are metals?
cork
paper
Q3.In which state do materials take the shape of the container they are held in?
In which state do materials take the shape of the container they are held in?
solid
gas
Q4.Match the form of water to the temperature range at which you would find it.
Match the form of water to the temperature range at which you would find it.
below 0°C
between 0 and 100°C
above 100 °C
Q5.Which of these materials would be the best thermal conductor?
Which of these materials would be the best thermal conductor?
rubber
plastic
glass
Q6.On a warm sunny day, if you put a scarf and hat on a snowman, how would it affect the speed the snowman melted?
On a warm sunny day, if you put a scarf and hat on a snowman, how would it affect the speed the snowman melted?
It would speed it up.
It would not affect it.
Assessment exit quiz
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6 Questions
Q1.Some solids dissolve in liquids to form a...
Some solids dissolve in liquids to form a...
solvent.
solute.
Q2.Solutions are always…
Solutions are always…
solid.
opaque.
Q3.Solutions…
Solutions…
are always colourless.
always have colour.
Q4.When a solid dissolves in a liquid, why can’t we see it anymore?
When a solid dissolves in a liquid, why can’t we see it anymore?
Because it becomes invisible in liquid.
Because it melts, making it harder to see.
Q5.What do you call a substance that dissolves in a liquid?
What do you call a substance that dissolves in a liquid?
insoluble
solvent
dissolvable
Q6.What do you call a substance that does not dissolve in a liquid?
What do you call a substance that does not dissolve in a liquid?
dissoluble
asoluble
unsoluble