Question

The energy required to dislodge electrons from cesium metal via the photoelectric effect is 207 kJ/mol . What wavelength (in nm) of light has sufficient energy per photon to dislodge an electron from the surface of cesium?

Answer 1

Answer:

So wavelength in nm will be $\lambda =0.956\times 10^{-19}nm$    

Explanation:

We have given that the energy = 207 KJ/mol $=207\times 10^3j/mol$

Speed of light $c=3\times 10^8m/sec$

Plank's constant $h=6.6\times 10^{-34}J-s$

According to plank's rule energy of the photon is given by

$E=\frac{hc}{\lambda }$

$207\times 10^3=\frac{6.6\times 10^{-34}\times 3\times 10^8}{\lambda }$

$\lambda =0.956\times 10^{-28}m$

So wavelength in nm will be $\lambda =0.956\times 10^{-19}nm$