Science lesson plan · 7th grade (Year 8 in England) · 45 minutes
Reactants, products and word equations
Chemical reactions, acids and bases
CCSS NGSS.MS-PS1-2CCSS NGSS.MS-PS1-5England: KS3 Chemistry: Chemical reactions
Objective and success criteria
Students will: Reactants, products and word equations.
- 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: Physical and chemical changes
Leads to: Neutralisation and naming salts; Exothermic and endothermic reactions; Balancing chemical equations
Materials: Teacher demo or video, Indicator color chart, Mini whiteboards, A diagram or short video clip of the idea, Printed student sheet (below).
Warm-up · 5 min
- Quick retrieval from earlier learning (Physical and chemical changes). Students answer on mini whiteboards.
- Show answers together and note who needs support in the main task.
- Is this a physical or a chemical change: baking bread? (physical change / chemical change) → chemical changePrompt: Is a new substance made?
- Which observation shows that a chemical reaction has happened? (The substance changes shape / Salt dissolves / Ice turns to water / A gas is given off and the colour changes) → A gas is given off and the colour changesPrompt: Look for signs of something new being made.
- Physical and chemical changes: which statement is NOT true? (Burning is a chemical change. / Rusting needs both oxygen and water. / Atoms are destroyed in chemical reactions. / In a chemical reaction, atoms are rearranged to make new substances.) → Atoms are destroyed in chemical reactions.Prompt: Does each change make a new substance?
Hook · 5 min
- Drop an antacid tablet in water (or show a clip) and ask whether a new substance is being made.
- Share the objective: Reactants, products and word equations. 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: Complete the word equation: calcium + oxygen → ___
- Step 1: calcium + oxygen → calcium oxide
- Step 2: So the answer is: calcium oxide
- Answer: calcium oxide
- 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.
- Complete the word equation: iron + oxygen → ___ (calcium oxide / carbon dioxide / iron carbonate / iron oxide) → iron oxidePrompt: A metal reacting with oxygen makes a metal oxide.
- Methane burns completely in air: methane + oxygen → carbon dioxide + ___ (nitrogen / water / carbon monoxide / hydrogen) → waterPrompt: Methane contains carbon and hydrogen. What does hydrogen become when it burns?
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.
- Why does a candle under a glass jar go out? (The oxygen inside is used up / The jar gets too heavy / Glass puts out flames / The wax turns into water) → The oxygen inside is used upPrompt: What does burning use from the air?
- Word equations: which statement is NOT true? (Combustion is a reaction with oxygen. / Burning metal makes it lighter because mass is lost. / Incomplete combustion can produce carbon monoxide, a poisonous gas. / Reactants are written on the left of the arrow.) → Burning metal makes it lighter because mass is lost.Prompt: Which side of the arrow is which?
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: Physical and chemical changes.
- Use concrete materials: teacher demo or video.
- 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: Neutralisation and naming salts; Exothermic and endothermic reactions; Balancing chemical equations.
- 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-7.
Free lesson plan from eurekami.com/lesson-plan-builder