Question

1. Explain using what you know about quantum vibration and infrared activity why the principal the constituents of the atmosphere (N2, O2, Ar etc…) are not greenhouse gases whereas carbon dioxide is a greenhouse gas. The greenhouse effect should be explained in your answer.

Answer 1

generally diatomic gases with two different atoms like CO & CO₂ have strong vibrational bands that makes them very good at absorbing & emitting infrared radiations in all directions, part of this radiation is directed towards the earth surface which results in warming the earth atmosphere known as greenhouse effect.

BUT molecules like N₂, O₂, Ar don't have strong vibrational bands so they are unable of absorbing & emitting radiations, hence they are not greenhouse gases.