What molecular feature allows Greenhouse Gases (GHGs) to absorb longwave infrared radiation?

Answer

They contain three or more atoms

GHGs absorb longwave infrared radiation because their molecular structure, containing three or more atoms (like $ ext{CO}_2$ and $ ext{H}_2 ext{O}$), allows the bonds to bend and stretch, causing the molecule to vibrate.

What molecular feature allows Greenhouse Gases (GHGs) to absorb longwave infrared radiation?
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