Science lesson plan · 5th grade (Year 6 in England) · 30 minutes
Reversible and irreversible changes
Materials and their properties
CCSS NGSS.2-PS1-4CCSS NGSS.5-PS1-4England: KS2 Y5 Properties and changes of materials
Objective and success criteria
Students will: Reversible and irreversible changes.
- I can answer questions on today's skill on my own, without help.
- I can explain each step and say why it works.
- I can check my answer and spot a mistake.
Before and after
Needs first: Dissolving and solutions
Leads to: Conservation of mass
Materials: A tray of everyday objects, Sorting hoops, Mini whiteboards, A diagram or short video clip of the idea, Printed student sheet (below).
Warm-up · 4 min
- Quick retrieval from earlier learning (Dissolving and solutions). Students answer on mini whiteboards.
- Show answers together and note who needs support in the main task.
- Is sand soluble or insoluble in water? (soluble (dissolves in water) / insoluble (does not dissolve)) → insoluble (does not dissolve)Prompt: Imagine stirring it into a glass of water. Would it disappear from view?
- 20 g of salt is dissolved in 200 g of water. What is the mass of the solution, in g? → 220 gPrompt: When something dissolves, does it disappear or is it still there?
- Sugar seems to disappear when it dissolves. Where does it go? (It floats away as gas / It breaks into tiny particles spread through the water / It turns into water / It is destroyed) → It breaks into tiny particles spread through the waterPrompt: Taste the water: is the sugar still there?
Hook · 3 min
- Pass round objects made of different materials and ask why each one was chosen.
- Share the objective: Reversible and irreversible changes. Read the success criteria together.
I do: model it · 7 min
- Work through the example out loud, saying why you do each step, not just what you do.
- Example: Is this change reversible or irreversible: melting butter?
- Step 1: A reversible change can be undone, like melting, freezing, dissolving and evaporating.
- Step 2: So the answer is: reversible
- Answer: reversible
- Pause after each step and ask a student to say what comes next.
We do: guided practice · 6 min
- Do these together. Students try each step on whiteboards before you reveal it.
- Use the hints as prompts rather than giving the answer.
- Is this change reversible or irreversible: mixing vinegar and bicarbonate of soda (baking soda)? (reversible / irreversible) → irreversiblePrompt: Could you get the starting material back?
- Which change is irreversible? (melting chocolate / melting butter / boiling water into steam / mixing vinegar and bicarbonate of soda (baking soda)) → mixing vinegar and bicarbonate of soda (baking soda)Prompt: Changes of state and dissolving can be reversed.
You do: independent practice · 7 min
- Students work on the student sheet. Circulate and check the first two answers of every student early.
- Students who finish: write a question of their own for a partner, with the answer.
The 6 questions are on the student sheet below, with answers in the key.
Exit ticket · 3 min
- Two questions on their own. Sort answers into got it / nearly / not yet to plan the next lesson.
- Is this change reversible or irreversible: mixing vinegar and bicarbonate of soda (baking soda)? (reversible / irreversible) → irreversiblePrompt: Could you get the starting material back?
- Why is burning a candle wick irreversible? (It can be turned back into a wick by cooling / New substances such as carbon dioxide and ash form / The wick only melts / Nothing new is made) → New substances such as carbon dioxide and ash formPrompt: What is left after burning?
Watch out for
- Everyday meanings of words getting in the way of the science meaning: define key words explicitly.
- Remembering facts without the reason: ask "why?" and "what is the evidence?"
Support and stretch
Support
- Review first: Dissolving and solutions.
- Use concrete materials: a tray of everyday objects.
- Give the first step of each question, or a partly worked example to finish.
- Pair with a confident partner for the guided practice.
Stretch
- Move on to: Conservation of mass.
- Explain a common mistake in writing and how to fix it.
- Write a word problem that uses today's skill, then solve a partner's.
Homework and more practice
Free online practice with hints and printable worksheets for this skill: eurekami.com/science/grade-5.
Free lesson plan from eurekami.com/lesson-plan-builder