Science lesson plan · 6th grade (Year 7 in England) · 45 minutes
Physical, chemical and biological weathering
Earth and rocks
CCSS NGSS.MS-ESS2-1CCSS NGSS.MS-ESS2-2England: KS3 Chemistry: Earth and atmosphere (the rock cycle)
Objective and success criteria
Students will: Physical, chemical and biological weathering.
- 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: Weathering and erosion
Leads to: the next skill in this area.
Materials: Rock samples, Hand lenses, Mini whiteboards, A diagram or short video clip of the idea, Printed student sheet (below).
Warm-up · 5 min
- Quick retrieval from earlier learning (Weathering and erosion). Students answer on mini whiteboards.
- Show answers together and note who needs support in the main task.
- Which type of weathering is this: water freezing and expanding in cracks? (physical weathering / chemical weathering / biological weathering) → physical weatheringPrompt: Is it caused by temperature and ice, by a chemical reaction, or by living things?
- What is the difference between weathering and erosion? (They are exactly the same / Weathering breaks rock down; erosion carries the pieces away / Weathering moves rocks to the sea / Erosion only happens in deserts) → Weathering breaks rock down; erosion carries the pieces awayPrompt: One breaks, the other moves.
- Which type of weathering is this: acid rain dissolving limestone? (physical weathering / chemical weathering / biological weathering) → chemical weatheringPrompt: Is it caused by temperature and ice, by a chemical reaction, or by living things?
Hook · 5 min
- Pass round different rocks and ask how each one might have formed.
- Share the objective: Physical, chemical and biological weathering. Read the success criteria together.
I do: model it · 10 min
- Work through the example out loud, saying why you do each step, not just what you do.
- Example: Which type of weathering is this: water freezes in a crack, expands and splits the rock?
- Step 1: Physical weathering breaks rock into pieces without changing its chemicals.
- Step 2: So the answer is: physical (freeze–thaw, heating and cooling)
- Answer: physical (freeze–thaw, heating and cooling)
- Pause after each step and ask a student to say what comes next.
We do: guided practice · 10 min
- Do these together. Students try each step on whiteboards before you reveal it.
- Use the hints as prompts rather than giving the answer.
- Which type of weathering is this: tree roots grow into cracks and widen them? (physical (freeze–thaw, heating and cooling) / chemical / biological) → biologicalPrompt: Is a living thing involved? Are new substances formed, or does the rock just break into pieces?
- What is the difference between weathering and erosion? (Weathering moves rocks to the sea / Weathering breaks rock down where it is; erosion carries the pieces away / Erosion only happens in deserts / They are exactly the same) → Weathering breaks rock down where it is; erosion carries the pieces awayPrompt: One process breaks; the other transports.
You do: independent practice · 10 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 8 questions are on the student sheet below, with answers in the key.
Exit ticket · 5 min
- Two questions on their own. Sort answers into got it / nearly / not yet to plan the next lesson.
- In which climate is freeze–thaw weathering most common? (in a hot desert that never freezes / where temperatures often go above and below 0 °C / in a tropical rainforest / under the sea) → where temperatures often go above and below 0 °CPrompt: Water must freeze and melt again and again.
- Which type of weathering is this: water freezes in a crack, expands and splits the rock? (physical (freeze–thaw, heating and cooling) / chemical / biological) → physical (freeze–thaw, heating and cooling)Prompt: Is a living thing involved? Are new substances formed, or does the rock just break into pieces?
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: Weathering and erosion.
- Use concrete materials: rock samples.
- Give the first step of each question, or a partly worked example to finish.
- Pair with a confident partner for the guided practice.
Stretch
- 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-6.
Free lesson plan from eurekami.com/lesson-plan-builder