Answer :
Answer:
[tex]1.95\cdot 10^{-10}m[/tex]
Explanation:
First of all, we need to calculate the energy of the x-ray photon emitted during the transition from K-shell to L-shell, and this energy is equal to the difference in energy between the two levels:
[tex]E=E_K-E_L=8500 eV-2125 eV=6375 eV[/tex]
Converting into Joules,
[tex]E=6375 eV \cdot (1.6\cdot 10^{-19} J/eV)=1.02\cdot 10^{-15} J[/tex]
Now we know that the energy of the photon is related to its wavelength by:
[tex]E=\frac{hc}{\lambda}[/tex]
where
h is the Planck constant
c is the speed of light
[tex]\lambda[/tex] is the wavelength
Re-arranging the equation for [tex]\lambda[/tex], we find
[tex]\lambda=\frac{hc}{E}=\frac{(6.63\cdot 10^{-34}Js)(3\cdot 10^8 m/s)}{1.02\cdot 10^{-15} J}=1.95\cdot 10^{-10}m[/tex]