Question

Calculate the wavelength of a photon whose wave number is $0.00143n{m}^{-1}$.

• A. $400nm$
• B. $500nm$
• C. $600nm$
• D. $700nm$

Answer 1

Answer: (D)

$700nm$

Wavenumber of a wave is defined as $\tilde{\nu }=\frac{1}{\lambda }$, where $\lambda$ is the wavelength.

Thus, wavelength $\lambda ={\tilde{\nu }}^{-1}$

Given that wavenumber of the photon is $\tilde{\nu }=0.00143{\text{nm}}^{-1}$

Thus, wavelength is $\lambda ={\tilde{\nu }}^{-1}=(0.00143{)}^{-1}\text{nm}\approx 700\text{nm}$