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 = 2xx 2.64 sin 7.75 ^(@) = 2xx 2.64 xx 0.1349`
` lambda = 0.712 Å`
Energy difference between K and L-shell of Mo `= (hc)/lambda = ( 6.626 xx 10^(-34) "Js" xx 3 xx 10^(8) ms^(-1))/( 0.712 xx 10^(-10) m) `
` 2.971 xx 10^(-15) J`