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Primary General Studies, People and the Environment, Paper 3: energy, food chains and landslides
Primary General Studies, People and the Environment, Paper 3: energy, food chains and landslides
Ten items on fossil fuels, producers in a food chain, sustainable development, heavy rain and slopes, wind and solar output, recovery rates, food miles and intermittent renewables.
Focus Coal, oil and gas are non-renewable fossil fuels; a food chain starts with a producer; sustainable development thinks of the next generation; heavy rain brings landslides; units are kW times hours; recovery rate is recovered over total; longer food miles mean more carbon; wind and solar need storage.
01 Paper details (check answers afterwards)
| Item | Detail |
|---|---|
| Questions | 10 |
| Suggested time | 25 |
| Difficulty mix | Foundation 4 · Intermediate 3 · Challenge 2 · Error redo 1 |
| Chapter | Chapter: Primary General Studies: People and the Environment |
| Level | P4 to P6 |
02 Questions (10 items)
- FoundationCoal, petroleum and natural gas are grouped as what, and can they be replaced?
- FoundationIn the food chain grass, rabbit, eagle, what is the role of the grass?
- FoundationWhat does sustainable development mean?
- FoundationWhy keep away from hillsides and retaining walls in heavy rain?
- IntermediateA 500 W wind turbine runs at full power for 4 hours. How many units does it make?
- IntermediateA solar panel makes 3 units a day. How many units in 30 days?
- IntermediateHong Kong produces about 11 000 tonnes of municipal solid waste a day with a 30% recovery rate. How many tonnes are recovered daily?
- ChallengeWhy does eating locally grown vegetables usually produce less carbon than air-freighted ones?
- ChallengeWhat limits wind and solar power?
- Error redoIs it right to put recyclables into the bin inside a plastic bag to keep it tidy?
03 Answers and one-line notes
| # | Answer | One-line note |
|---|---|---|
| 1 | Fossil fuels, and they are non-renewable. | They formed from ancient living things over millions of years and cannot be replaced. |
| 2 | It is the producer. | Green plants make food from sunlight, so they start the chain and the rabbit is a consumer. |
| 3 | Meeting present needs without harming the ability of future generations to meet theirs. | Cutting waste and saving energy leave resources for the next generation. |
| 4 | Rain loosens the soil and landslides can happen. | Hong Kong is hilly and wet, so a landslide warning means staying in a safe place. |
| 5 | 2 kWh. | Units equal kW times hours: 500 / 1000 x 4 = 2 kWh. |
| 6 | 90 kWh. | 3 x 30 = 90 kWh, though real output is lower on cloudy days. |
| 7 | About 3 300 tonnes. | 11 000 x 30% = 3 300 tonnes, and the rest goes to landfill. |
| 8 | Shorter food miles mean less transport fuel and shorter refrigeration. | Air freight emits far more carbon per kilogram than road or sea transport. |
| 9 | Output varies with weather and daylight, so storage or other sources are needed. | A grid mixes different sources so supply stays steady. |
| 10 | No. They should go in clean, dry and loose; a bag gets in the way of sorting. | Bagged recyclables are often thrown away whole, which lowers the recovery rate. |
04 What to do after marking
- After marking, redo only the wrong items and write down which step went wrong (formula, unit, or misread number).
- Repeat the same item two days later; move to the next paper only when both attempts are correct.
- Parents only need the answer and note columns; there is no need to explain every item.
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