When an electron in an excited state of Mo atom falls L to K -shell, an X -ray is emitted. These X -rays are diffranted at angle of ` 7.75^(@)` by planes with a sepration of 2.64Å . What is the difference in energy between K-shelll and L -shell in Mo, assuming a first order diffraction ? ` ( sin 7.75^(@) = 0.1349)

Explanation

According to Bragg's equation :
`n lambda =2 d sin theta`
`1 xx lambda=2xx2.64 sin 7.75^@ =2xx2.64 xx0.1349`
`lambda`=0.712 Å
Energy difference between K and L-shell of Mo=`"hc"/lambda=(6.626xx10^(-34)Js xx 3xx10^8 ms^(-1))/(0.712xx10^(-10)m)`
`=2.791xx10^(-15) J`