More reversible changes
Lesson details
Learning outcome
I can demonstrate how mixing and dissolving are reversible changes
Key learning points
- If a change is reversible, it can be undone or changed back to its original state.
- A mixture is material that contains two or more different substances, which can be physically separated.
- When a soluble solid dissolves, it is broken down to become so tiny we can no longer see it, but it is still there.
- Dissolving is a reversible process. Evaporation can be used to recover soluble solids from solutions.
Keywords
State - The three common states of matter are solid state, liquid state and gas state.
Recover - To recover is to get back something that had changed or was taken away.
Reversible - If a change is reversible, it can be undone or changed back to its original state.
Dissolve - If a solid dissolves in a liquid, it mixes so completely with the liquid that it cannot be seen.
Mixture - A mixture can be physically separated.
Common misconception
Changes in state and dissolving and mixing are not reversible processes.
Teaching slides will show which processes can be used to reverse state changes and dissolving. This will be explored and embedded during the practice tasks.
Teacher tip
Encourage children not to say that a solid has disappeared when it has dissolved but to recognise that it has broken down to become so tiny we can no longer see it, but it is still there.
Equipment
Equipment and materials for making lemonade and then to separate the original materials from a sample of it. See additional materials.
Content guidance
Risk assessment required - equipment
Exploration of objects
Supervision
Adult supervision required
Licence
Lesson video
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Prior knowledge starter quiz
6 Questions
Q1.Which of these are states of matter?
Q2.At what temperature does liquid water change to ice?
Q3.Match the name of the process to the description:
Q4.What happens when you stir sand in water?
Q5.A substance dissolves in a liquid.
Q6.True or false? You can recover a dissolved solid from a solution by filtration.
Assessment exit quiz
6 Questions
Q1.If a change is reversible …
Q2.What process can be used to reverse evaporation?
Q3.A mixture is material that contains two or more different substances, which can be physically ...
Q4.What happens to a soluble solid when it dissolves?
Q5.Is making a mixture a reversible or irreversible process?
Q6.How can you recover dissolved solids from a solution?
To help you plan your 5 science lesson on: More reversible changes, download all teaching resources for free and adapt to suit your pupils' needs...
To help you plan your 5 science lesson on: More reversible changes, download all teaching resources for free and adapt to suit your pupils' needs.
The starter quiz will activate and check your pupils' prior knowledge, with versions available both with and without answers in PDF format.
We use learning cycles to break down learning into key concepts or ideas linked to the learning outcome. Each learning cycle features explanations with checks for understanding and practice tasks with feedback. All of this is found in our slide decks, ready for you to download and edit. The practice tasks are also available as printable worksheets and some lessons have additional materials with extra material you might need for teaching the lesson.
The assessment exit quiz will test your pupils' understanding of the key learning points.
Our video is a tool for planning, showing how other teachers might teach the lesson, offering helpful tips, modelled explanations and inspiration for your own delivery in the classroom. Plus, you can set it as homework or revision for pupils and keep their learning on track by sharing an online pupil version of this lesson.
Explore more key stage 2 science lessons from the Properties, changes and separating materials unit, dive into the full primary science curriculum, or learn more about lesson planning.