Year 10 Science · Unit 4 · Lesson 9
Apply Worksheet
Learning Goals
Compare two
Complete the table to compare the linear and circular economy models. Fill in all blank cells.
| Feature | Linear economy | Circular economy |
|---|---|---|
| Basic flow of materials | ||
| What happens to a product at the end of its life | ||
| Effect on raw resource use | ||
| Amount of waste generated |
Real-world context
A student's three-year-old smartphone has a cracked screen and a weak battery, but the rest of the phone still works. The student is deciding between three options: (1) recycle the phone for its metals and buy a brand-new one, (2) replace the screen and battery and keep using it, or (3) sell or donate it so someone else can use it after a repair. The student wants to make the most sustainable choice using the circular economy hierarchy.
(a) Rank the three options from most sustainable to least sustainable using the circular economy hierarchy. Justify your ranking.
(b) Explain why recycling the phone, even though it recovers metals, has a larger environmental impact than repairing and keeping it.
(c) Beyond the student's own choice, name one systemic change (a government or company action) that would make the sustainable option easier for everyone, and explain how it would help.
Wrap Up
In one sentence, what was the main idea of this lesson?
For teacher or self-marking use. Accept answers with the same meaning.
Compare two
Basic flow of materials. Linear: take, make, waste (a one-way flow). Circular: materials are kept in a loop and reused, repaired, remanufactured, or recycled.
End of life. Linear: the product is thrown away to landfill or incinerated. Circular: the product (or its materials) is reused, repaired, remanufactured, or recycled back into use.
Effect on raw resource use. Linear: high; new raw materials are extracted for every product. Circular: lower; existing materials are reused so fewer new resources are needed.
Waste generated. Linear: large amounts of waste. Circular: little or no waste, because waste is designed out of the system.
Your Turn
(a) Most to least sustainable: Option 2 (repair and keep) is most sustainable because repair sits high in the hierarchy and keeps the whole product in use. Option 3 (sell or donate after repair) is next, because reuse by another person keeps the product in use but involves transport and a repair. Option 1 (recycle and buy new) is least sustainable, because recycling is the last resort and buying a new phone requires extracting and processing new materials. Accept Option 2 and Option 3 ranked either way if justified, provided Option 1 is placed last.
(b) Recycling still uses energy to collect, sort, shred, and process the phone, and it usually recovers only some materials at lower quality (downcycling), losing the value built into the working components. Repairing keeps the existing screen, board, and casing in use, avoiding both the recycling energy and the much larger impact of manufacturing a whole new phone.
(c) One mark for naming a valid systemic change, e.g. right-to-repair laws, producer-responsibility schemes for e-waste, a single-use plastics ban, or requiring spare parts to be available. Up to two marks for explaining how it helps, e.g. right-to-repair laws force manufacturers to supply parts and repair information, lowering the cost and difficulty of repair so more people choose to repair rather than replace.