Fossil Fuels
Name the three main fossil fuels.
Coal, petroleum (oil), and natural gas.
Which renewable technology converts sunlight directly into electricity without using a turbine?
Solar photovoltaic (PV) cells.
What is an energy gap?
A situation in which energy demand is greater than the available energy supply.
What type of rock is targeted when natural gas is extracted by fracking?
Shale rock.
Which country generates almost all its electricity using hydroelectric and geothermal energy?
Iceland.
Why are fossil fuels classified as non-renewable?
They take millions of years to form, much more slowly than humans consume them.
What is the function of a generator in an electricity power station?
To convert mechanical (kinetic) energy into electrical energy.
Question: Name two ways to reduce heat loss from a house.
Any two: roof or wall insulation, cavity wall insulation, double/triple glazing, or reducing unwanted air leakage.
What is the name and purpose of the sand used during fracking?
Proppant; it keeps fractures in the shale rock open so oil or gas can flow.
Name two factors that can influence a country's demand for energy.
Any two: population size, climate, transport, personal or national wealth, industry, supply disruption, unreliable supply, or resource scarcity.
Put these stages of coal formation in order: coal, peat, lignite.
Peat → lignite → coal.
What causes turbines to rotate in a hydroelectric power station?
Flowing or falling water.
How does battery storage help manage electricity from solar panels or wind turbines?
It stores excess electricity when supply is high and releases it later when supply is low or demand is high.
Name the three main ingredients injected underground at high pressure during fracking.
Water, sand (proppant), and chemical additives.
The Three Gorges Dam produces large amounts of electricity. Identify one benefit and one social or environmental limitation.
Benefit: large electricity output, flood control, or improved navigation. Limitation: relocation of communities, flooding of habitats and cultural sites, or alteration of river systems.
Why can wood be a renewable energy resource while coal is not?
Trees can regrow on a human timescale if they are replaced sustainably, whereas coal takes millions of years to form.
What process releases the heat used to generate electricity in a nuclear power station?
Nuclear fission, which splits uranium nuclei and releases heat.
A house uses 15 litres of heating oil per square metre annually. Improved insulation reduces this by 90%. How much oil is used afterward?
1.5 litres per square metre annually (15 × 0.10 = 1.5).
Explain two possible ways fracking operations can contaminate water.
Any two: surface chemical or wastewater spills; defective well casing or cement; leaks from poorly managed wastewater storage; inadequate wastewater treatment.
A remote village has strong sunlight but needs electricity at night. Recommend two complementary technologies and explain how they would work together.
Solar photovoltaic panels generate electricity in daylight, and battery storage stores surplus daytime electricity for use at night.
Explain one difference between how coal forms and how petroleum and natural gas form.
Coal mainly forms from buried swamp or land vegetation, while petroleum and natural gas mainly form from buried marine organisms under heat and pressure.
Describe the sequence of energy transformations from water stored behind a hydroelectric dam to the electricity produced.
Gravitational potential energy → kinetic energy of flowing water → mechanical energy of the turbine → electrical energy from the generator.
Explain how green hydrogen and blue hydrogen differ in their production and environmental impacts.
Green hydrogen is produced by electrolysis using renewable electricity. Blue hydrogen is produced from natural gas with carbon capture, but still relies on a finite fossil fuel and can cause residual CO₂ and methane emissions.
Most induced earthquakes during Oklahoma's oil and gas boom were associated with which activity: hydraulic fracturing itself or deep wastewater disposal? Explain.
Deep wastewater disposal. Long-term injection into disposal wells increased underground fluid pressure and triggered earthquakes. Most were not directly caused by the fracturing stage
A government proposes fracking to solve its energy gap. Give two potential benefits, two environmental risks, and one alternative energy-management strategy.
Benefits: more domestic gas supply and jobs (or reduced imports). Risks: water contamination, induced earthquakes, methane leakage, or habitat disturbance. Alternative: improve energy efficiency, develop renewables, use insulation, or expand storage.