Answer: inactivates the catalyst.
- A raises the engine mileage
- B cools the running engine
- C cleans the exhaust gases
- D inactivates the catalyst
Correct answer: D. inactivates the catalyst
Explanation: Leaded petrol coats and inactivates the platinum-palladium-rhodium catalyst, so vehicles fitted with catalytic converters must use only unleaded petrol.
Sunlight passes through the atmosphere and warms the surface; the surface re-radiates this energy as infrared heat, which greenhouse gases (CO₂, CH₄, water vapour) absorb and trap - a naturally beneficial process that intensifies into global warming as gas concentrations rise from human activity.
Concept context
Pollution, global warming, ozone depletion, deforestation, and sustainability. Important for NEET and general awareness.