Question

What will be the wave number of yellow radiation having wavelength 240 nm?

• A. $1.724\times {10}^{4}c{m}^{-1}$
• B. $4.16\times {10}^6{m}^{-1}$
• C. $4\times {10}^{14}Hz$
• D. $\mathrm{2.19.3}\times {10}^{3}c{m}^{-1}$

Answer 1

The correct option is B $4.16\times {10}^6{m}^{-1}$

Wavelength of yellow light, $\lambda =240nm=240\times {10}^{-9}m$

Wavenumber $\stackrel{\_}{\nu }=\frac{1}{\lambda }=\frac{1}{240\times {10}^{-9}}=4.16\times {10}^6{m}^{-1}$

option B