Question

use the diagram to sort each gas according to whether or not it can absorb infrared (ir) radiation.
oxygen
carbon dioxide
methane
water vapor
absorbs ir radiation
does not absorb ir radiation

Explanation:

Step1: Recall IR absorption of gases

Greenhouse gases (CO₂, CH₄, H₂O vapor) absorb IR; diatomic gases like O₂, N₂ do not (symmetric, no dipole change).

Step2: Categorize each gas

• Absorbs IR: Carbon dioxide (CO₂), Methane (CH₄), Water vapor (H₂O). These are greenhouse gases with molecular structures allowing dipole moment changes during vibration, enabling IR absorption.
• Does not absorb IR: Oxygen (O₂), Nitrogen (N₂) (not shown in options here, but O₂ is diatomic, symmetric, no dipole change on vibration). Wait, the options given: Oxygen, Carbon dioxide, Methane, Water vapor. So:
• Absorbs IR: Carbon dioxide, Methane, Water vapor.
• Does not absorb IR: Oxygen.

Answer:

Absorbs IR radiation: carbon dioxide, methane, water vapor
Does not absorb IR radiation: oxygen