Chapter 10, Problem 10.126SP

Interpretation Introduction

Interpretation:

Whether the given symmetric and anti-symmetric modes of methane would absorb IR radiation should be decided.

Concept introduction:

The gases that cannot absorb IR radiation are termed as IR inactive and categorized into greenhouse gases. The two such gases are abundant in the atmosphere such as ${\text{O}}_{\text{2}}$ and ${\text{N}}_{\text{2}}$. Toexhibit IR activity, any molecule must exhibit a progressive change in dipole moment in its vibrational modes. For instance, the anti-symmetric mode of ${\text{CO}}_{\text{2}}$ shows a fluctuation in dipole moment and hence is IR active.