Students explain that the lithosphere is divided into moving plates and describe mantle convection, driven by Earth's inner heat (from the core and from radioactive decay in the mantle), as the mechanism (AC9S8U03, node 2, a hinge node).
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 10 min · Evaluate 3 min · Typical adds 4 min, Wider about 5 min
A concept tutorial for introducing or revising the idea; it does not replace a convection demonstration. Set the width with ?width=minimum, typical (default) or wider.
The hinge risk is plate movement with no mechanism: without convection, boundary features (nodes 3 to 5) look arbitrary.
Assumed: convection, and density from Year 7 (less dense rises). These tutorials teach convection in Year 9 (Heat transfer), so Explore opens with a one-question recap (warm fluid rises because it is less dense). If the class has not met convection, demonstrate it first (see In class, below).
Model notes, worth saying aloud: the board draws the mantle as moving particles, but the real mantle is solid rock that flows over millions of years. In the model hot particles are pushed up directly; real hot rock rises because it is less dense. The plates on top move with the surface flow.
Giving a mechanism: mantle convection carries the plates. When a student says heat rises, ask what is actually moving up on the board.
| What you will see | A question to ask | The fix |
|---|---|---|
| A student says the plates float on liquid magma. | Is the mantle liquid? | No: it is solid rock that flows extremely slowly. Magma forms only in small pockets. |
| A student says heat rises. | What is actually moving up on the board? | Hot rock moves up, because it is less dense. Heat travels with it. |
| A student says earthquakes move the plates. | Which comes first: the plates moving or the earthquake? | Plates move and stick; when they slip, we feel an earthquake. Convection moves the plates. |
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: The Australian continent's centre has some of the oldest, most stable rock on Earth. Use the board to suggest why the middle of a plate is quieter than its edges.
Support: Give a four-box cycle diagram (heated, rises, cools, sinks) to fill in while watching the board.
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 ONE idea only, from the lesson "What moves the plates?". The idea: Tectonic plates and the driving mechanism: I can explain that the lithosphere is divided into tectonic plates and describe mantle convection as the mechanism driving plate movement. What understanding looks like: - Explains that the lithosphere is divided into tectonic plates that move - Describes mantle convection as the mechanism driving plate movement - States that plates move at rates of centimetres per year Mistakes students often make here: - A student says the plates float on liquid magma. - A student says heat rises. - A student says earthquakes move the plates. 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 (Earth's internal structure — layers, states and the lithosphere), 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 "What moves the plates?".
What drives the movement of tectonic plates?
Convection currents in the mantle: heated rock rises, spreads, cools and sinks, carrying the plates. The heat comes from the core and from radioactive elements in the mantle.
Next: what happens where plates meet: divergent (node 3), convergent (node 4) and transform (node 5) boundaries.
In class: a beaker of water heated from one side with a few potassium permanganate crystals or food colouring, and a raft of paper on top.