Loading…
Loading…
GCSE Chemistry · key term
Long-wavelength electromagnetic radiation emitted by warm objects, including the Earth’s surface.
Used by AQA and OCR
Specification 4.9.2.1 · Paper 2
Electromagnetic radiation emitted by warm objects; Earth’s warmed surface emits long-wavelength infrared radiation.
Revise: Greenhouse GasesAfter Earth’s surface absorbs some of this radiation, it warms and emits radiation with a longer wavelength, mainly infrared radiation.
Specification C6.3c · Paper 2 (Foundation), Paper 4 (Higher)
Electromagnetic radiation emitted strongly by the warm Earth’s surface and absorbed by greenhouse gases.
Revise: The Greenhouse EffectThe main gases in the atmosphere, nitrogen and oxygen, do not absorb much of the outgoing infrared radiation. Greenhouse gases—including water vapour, carbon dioxide and methane—can absorb infrared radiation at particular wavelengths.
Paper 1 (Foundation), Paper 2 (Foundation), Paper 3 (Higher), Paper 4 (Higher)
Revise: The greenhouse effectBecause the Earth is much cooler than the Sun, its radiation has longer wavelengths and is mainly infrared radiation.
Describe a sequence: incoming short-wave radiation → absorption by the Earth’s surface → emission of long-wave infrared radiation → absorption and re-emission by greenhouse gases.
Refer to infrared radiation, not simply “heat being trapped”. Greenhouse gases absorb and re-emit radiation; they do not form a solid barrier.
State that greenhouse gases absorb only particular wavelengths of infrared radiation, rather than all radiation.
Create a free account to read GCSE Chemistry revision notes for your exam board and track your progress.