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: crushing a can? (physical change / chemical change) → physical changePrompt: Is a new substance made?
- A nail left outside turns orange-brown and flaky. What has happened? (Iron reacted with oxygen and water to make rust / The nail melted / The nail dissolved / Paint fell on it) → Iron reacted with oxygen and water to make rustPrompt: Rusting needs both air and water.
- Physical and chemical changes: which statement is NOT true? (Rusting needs both oxygen and water. / Atoms are destroyed in chemical reactions. / In a chemical reaction, atoms are rearranged to make new substances. / Burning is a chemical change.) → 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: zinc + oxygen → ___ (zinc oxide / zinc chloride / calcium oxide / carbon dioxide) → zinc oxidePrompt: A metal reacting with oxygen makes a metal oxide.
- In the reaction "iron + sulfur → iron sulfide", what are the reactants? (iron only / iron and sulfur / sulfur and iron sulfide / iron sulfide) → iron and sulfurPrompt: Reactants are on the left of the arrow.
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.
- What is needed for fuels to burn? (nitrogen only / carbon dioxide / oxygen and enough heat / water and light) → oxygen and enough heatPrompt: Think of the fire triangle: fuel, heat and…
- Word equations: which statement is NOT true? (Combustion is a reaction with oxygen. / Thermal decomposition breaks a substance down using heat. / The arrow in a word equation means "equals". / Reactants are written on the left of the arrow.) → The arrow in a word equation means "equals".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