This memory aid covers Memory Aid within Greenhouse Effect for GCSE Chemistry. Revise Greenhouse Effect in Atmosphere for GCSE Chemistry with 25 exam-style questions and 12 flashcards. This topic appears regularly enough that it should still be part of a steady revision cycle. It is section 10 of 14 in this topic. Use it for quick recall, then test yourself straight afterwards so the memory aid becomes usable in an answer.
🧠 Memory Aid
Greenhouse gases ABSORB infrared radiation and RE-EMIT it back to Earth — these are the two key words for mark schemes
For greenhouse gases: "CO₂, CH₄, H₂O — the 3 C's-M-W" (Carbon dioxide, Methane, Water)
For the mechanism: "Short-wave IN, long-wave ABSORBED and RE-EMITTED back — remember both words for full marks"
Temperature without greenhouse effect: "-18°C = freezing death. With natural effect: +15°C = life. With enhanced effect: above +15°C = problem."
Quick Check: Explain why nitrogen is NOT a greenhouse gas even though it makes up 78% of the atmosphere.
Nitrogen (N₂) does not absorb infrared radiation because of its symmetrical molecular structure. Only molecules like CO₂, CH₄, and H₂O have a structure that allows them to absorb infrared radiation. Greenhouse gases must be able to absorb and re-emit infrared radiation — N₂ cannot do this.
Practice questions for Greenhouse Effect
Which of these gases is NOT a greenhouse gas?
Explain why the natural greenhouse effect is important for life on Earth.