Students explain exothermic and endothermic reactions as energy released to or absorbed from the surroundings, and classify everyday reactions (AC9S8U07, nodes 4 and 5).
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 8 min · Explain 9 min · Evaluate 3 min · Typical adds 3 min, Wider about 2 min
A concept tutorial for introducing or revising the idea; it is best beside a hands-on test with a thermometer (citric acid and bicarb gets colder; magnesium in acid gets hotter). Set the width with ?width=minimum, typical (default) or wider. One lesson for two nodes, after How can you tell a reaction happened?
Neither is a hinge node. The misconception: cold is a thing that flows ("cold energy"). The prediction targets it.
Board notes: the reaction board warms or cools the gas as reactions give out or take in energy. The endothermic reaction (nitrogen + oxygen → nitrogen monoxide) is real but only happens at engine temperatures; it starts at 600 K and cools. Both reactions stop at their target.
Thinking about the surroundings, not the reaction. When a student says 'the reaction gets cold, so it gives out cold', ask where the energy went and let them redraw the arrow.
| What you will see | A question to ask | The fix |
|---|---|---|
| A student says the ice pack gives out cold. | Is cold something you can add, or is it less of something? | Less thermal energy. The reaction takes energy in from your hand, so your hand cools. |
| A student mixes up exo and endo. | Exit means out. Which one sends energy out? | Exothermic: energy out, surroundings hotter. |
| A student thinks photosynthesis is exothermic because the Sun is hot. | Does the plant take light energy in or give it out? | It takes it in to make glucose: endothermic. |
One possible solution for each task. Other correct programs are fine.
Open task: any program that does what the step asks.
Open task: any program that does what the step asks.
Stretch: Respiration and photosynthesis are almost the reverse of each other. Why is one exothermic and the other endothermic? (Photosynthesis stores light energy in glucose; respiration releases it.)
Support: Give the frame: 'In an … reaction, energy moves from … to … , so the surroundings get … .'
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 8 student in Australia. Help me understand the ideas in ONE lesson only, from the lesson "Hotter or colder?". The ideas: - Exothermic reactions — energy released to surroundings: I can identify exothermic reactions by temperature rise, explain that energy is released as bonds form in the products, and give examples. - Endothermic reactions — energy absorbed from surroundings: I can identify endothermic reactions by temperature drop, explain that energy is absorbed to break reactant bonds, and give examples. What understanding looks like: - Identifies exothermic reactions by a temperature rise in the surroundings - Explains that exothermic reactions release energy stored in chemical bonds - Gives at least two examples of exothermic reactions - Identifies endothermic reactions by a temperature fall in the surroundings - Explains that endothermic reactions absorb energy from surroundings - Gives at least two examples of endothermic reactions and distinguishes them from exothermic Mistakes students often make here: - A student says the ice pack gives out cold. - A student mixes up exo and endo. - A student thinks photosynthesis is exothermic because the Sun is hot. 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. - If I seem to be missing the idea that comes before this one (Observable indicators of chemical change), check it quickly, then come back. - 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 "Hotter or colder?".
Burning candle wax: exothermic or endothermic? Explain using the word surroundings.
Exothermic: the reaction gives out energy to the surroundings, which get hotter (and light is given out).
Next: comparing physical and chemical changes with every criterion (node 6) is a class task. Year 9 energy conservation and Year 10 collision theory build on this.
In class: thermometer readings for citric acid + bicarb (endothermic) and magnesium + dilute acid (exothermic).