Chapter 15, Problem 15.15P

Interpretation Introduction

Interpretation:

The wavelengths of the photons required to excite three vibrations indicated in Figure 15-12 are to be calculated.

Concept introduction:

The wavenumber ($\overline{\text{ν}}$) is calculated by dividing 1 by the wavelength ($\text{λ}$) in centimeters as

${\overline{\text{ν}}\text{(in cm}}^{\text{-1}}\text{) =1/(wavelength in cm)}$.

The two common units of frequency ($\text{ν}$)—${\text{cm}}^{\text{-1}}$ and Hz are related by the speed of light as

${\overline{\text{ν}}\text{(in cm}}^{\text{-1}}\text{)=ν (in Hz)/(100 c)}$. (The factor of 100 accounts for different units of length used for wavenumbers and the speed of light: cm for wave numbers and m for the speed of light.)

The frequency ($\text{ν}$) is calculated by dividing speed of light by wavelength ($\text{λ}$) as $\text{ν = c / λ}$.