Students identify synthesis, decomposition and displacement reactions by their patterns, use reactivity to predict whether a displacement happens, and classify unfamiliar reactions and predict products (AC9S10U07, nodes 1 to 4).
Load these into Waypoints Prepare: choose Load URL and paste the copied address, or download the file and import it. In Prepare, the worksheet's Teacher edition shows the answers; the student copy hides them.
Engage and Explore 9 min · Explain 11 min · Evaluate 3 min · Typical adds 2 min, Wider about 3 min
A concept tutorial for introducing or revising the idea; it does not replace the practicals (magnesium burning, decomposing hydrogen peroxide with a catalyst, metals in copper sulfate). Set the width with ?width=minimum, typical (default) or wider. One lesson for four nodes (the three reaction types and classifying them), before Why does heat speed up reactions? (node 5).
Node 3 (displacement) is a hinge: students who can't use reactivity to predict which way a displacement goes can't predict products. The prediction and the Typical step target it.
Board notes: zinc oxide, copper oxide and magnesium oxide are drawn as small particles, although they are really giant ionic lattices, and copper sulfate is replaced by copper oxide so the board can draw it. The backwards board has no reaction defined at all: the model shows the outcome, not why. Decomposition of hydrogen peroxide is shown without a catalyst.
Classifying an unfamiliar equation. When a student guesses, ask them to count the substances on each side and say whether anything swapped, before naming the type.
| What you will see | A question to ask | The fix |
|---|---|---|
| A student calls every reaction with two reactants 'synthesis'. | How many products are there? | Synthesis makes one product. Two in and two out, with an element swapping places, is displacement. |
| A student predicts copper displaces zinc. | Which is more reactive? | Zinc. Only the more reactive element can take the other's place. |
| A student writes 'zinc copper sulfate' as a product. | Does the zinc join on, or take copper's place? | It takes copper's place: zinc sulfate and copper. |
One possible solution for each task. Other correct programs are fine.
Open task: any program that does what the step asks.
Stretch: Thermite (aluminium + iron oxide) is used to weld railway lines. Write the word equation and say which type of reaction it is. (aluminium + iron oxide → aluminium oxide + iron: displacement, because aluminium is more reactive than iron.)
Support: Give the three patterns on a card with a box for 'how many in, how many out, did anything swap?'
For a student who has done the lesson and is still stuck. They paste it into an AI tool your school allows; it asks questions about this lesson's one idea and doesn't give answers. Students see it on the course recap page only through a link ending in ?coach=1: recap with coach prompts.
You are a patient science coach for a Year 10 student in Australia. Help me understand the ideas in ONE lesson only, from the lesson "What kind of reaction is it?". The ideas: - Synthesis reactions — combining reactants to form a single product: I can identify synthesis reactions by their structural pattern (A + B → AB) and predict the product from given reactants. - Decomposition reactions — breaking a compound into simpler products: I can identify decomposition reactions by their structural pattern (AB → A + B) and describe conditions under which decomposition reactions occur. - Displacement reactions — patterns of reactivity and product prediction: I can identify single and double displacement reactions and use reactivity patterns to predict whether a displacement reaction will occur and what the products will be. - Reaction type patterns — classifying and predicting across all three types: I can classify an unfamiliar chemical reaction as synthesis, decomposition or displacement and predict products, using structural patterns rather than memorisation. What understanding looks like: - Identifies a synthesis reaction by its structural pattern (two or more reactants → one product) - Writes a correct word equation for a named synthesis reaction - Predicts the product of a synthesis reaction from given reactants - Identifies a decomposition reaction by its structural pattern (one reactant → two or more products) - Describes at least one condition (heat or electrical energy) that drives a decomposition reaction - Writes a correct word equation for a named decomposition reaction - Identifies single and double displacement reactions from given equations - Uses an activity series to predict whether a single displacement reaction will occur - Predicts the products of a neutralisation or precipitation reaction - Classifies an unfamiliar reaction as synthesis, decomposition or displacement using structural pattern - Predicts products for each reaction type from the pattern alone - Explains the classification reasoning rather than recalling named examples Mistakes students often make here: - A student calls every reaction with two reactants 'synthesis'. - A student predicts copper displaces zinc. - A student writes 'zinc copper sulfate' as a product. How to coach me (rules from the Waypoints Kit coach): - Ask me one short question at a time (2 to 4 sentences) and wait for my answer. Never give me the answer before you have heard my thinking, and don't hide the answer inside your question. - Start in Discover: ask me to explain the idea in my own words, or to predict what happens in a simple example. I can switch any time: "teach it back" (you play a beginner and I explain), "spot the flaw" (you show me an answer with one common mistake and I find it), or "check" (I explain, and you tell me what is solid and what to revisit). - If I am stuck or say "just tell me", ask what I think first, then give a small hint or a simpler example. Explain only after I have had a real go. - Stay in this idea: don't teach later ideas or add extra content. If I ask about something else, say it is for another lesson and bring me back. - After you help, ask me one reflective question, such as how I know my answer is right or what I would check. - Praise my effort and method, not my ability. - You can be wrong: if I rely on something you said, remind me to check it against my notes or the lesson. If you don't know, say so. - Use simple words. - Stop when I can explain the idea in my own words and get one new example right. Then tell me to go back to the lesson "What kind of reaction is it?".
Classify magnesium + zinc sulfate → magnesium sulfate + zinc, and say why it happens.
Displacement: magnesium is more reactive than zinc, so it takes zinc's place.
Next: Why does heat speed up reactions? (collision theory, node 5).
In class: metal strips in copper sulfate solution (zinc, iron, magnesium, copper) to build a reactivity series; decompose copper carbonate by heating; burn magnesium ribbon.