Resource conservation means using resources carefully so they last longer and cause less harm. A full answer gives the action, says what it does to the resource, and adds a reason.
This lesson belongs to SPM Science green technology. For waste methods in more depth, see comparing waste management approaches.
What makes an explanation complete?
Use three parts: the action, its effect on the resource, and the reason. A weak answer stops after the action.
Pattern: “Action, which means less or longer use of the resource, because the reason.” The word because is what turns a statement into an explanation.
Worked example: a school bottle project
A school collects 240 plastic bottles each week. It recycles 60% of them and sends the rest to landfill.
Recycled bottles per week. 240 × 60 ÷ 100 = 144 bottles.
Over 40 school weeks. 144 × 40 = 5 760 bottles are kept out of landfill.
Now write the explanation. “Recycling the bottles conserves the raw material used to make new plastic, because the used plastic is processed into new items. Over 40 school weeks it also keeps 5 760 bottles out of landfill, so the landfill lasts longer.”
The answer has the action, the effect on the resource and the reason. It also uses the calculated number to support the point.
Reduce, reuse, recycle: how do they differ?
The three actions save resources at different stages. Reduce avoids using the resource, reuse uses an item again, and recycle reprocesses the material.
| Action | What happens | Example | Reason it conserves |
|---|---|---|---|
| Reduce | Use less from the start | Bring a cloth bag | Less raw material is taken |
| Reuse | Use the same item again | Refill a water bottle | No new item needs making |
| Recycle | Process used material into new items | Melt old glass | Less new raw material is needed |
The mistake that costs marks
The usual slip is to write reuse when the question describes recycling. A student says “we reuse old paper to make new paper”, which is recycling, since the paper is broken down and remade.
| Situation | Wrong | Right |
|---|---|---|
| Used paper pulped into new paper | Reuse | Recycle |
| A jar refilled with sauce | Recycle | Reuse |
| Buying only what is needed | Recycle | Reduce |
The fix is to ask one question: is the item used as it is, or is the material reprocessed? The answer decides the word.
Check yourself
A family fills a rainwater tank and uses the water to wash a car. Explain how this conserves a resource. Then state which of reduce, reuse or recycle fits best.
Answer
Using stored rainwater means less treated tap water is needed, because the rain replaces it for this job. The treated water supply lasts longer.
It fits reduce, since the demand for treated water falls. Some textbooks group rainwater collection under reuse, so follow your textbook.
What to study next
Next, use these explanations to judge statements: evaluating claims using a stated criterion. Then try the green technology practice set.
The graph evidence and fair-comparison lab helps with reading tables. If you want a teacher to ask for the reason behind each answer, see online one-to-one Science tuition.