Continuous X-rays are made to strike a tissue paper soaked with polluted water. The incoming X-rays excite the atoms of the sample by knocking out the electrons form the inner shells. Characteristic X-rays are subsequently emitted. The emitted X-rays are analysed and the intensity is plotted against the wavelength (figure 44*E1). Assuming that only `K_alpha` intensities are detected, list the elements present in the sample from the plot. Use Moseley's equation. `v = (25 xx 10^(14) Hz) (Z - 1)^(2)`.

Explanation

Given `f=(25xx10^14Hz)(Z-1)^2 `
` or, c/lambda=25xx10^14(Z-1)^2 `
` (a) (3xx10^8)/(78.9xx10^-12xx25xx10^14)=(Z-1)^2 `
`or (Z-1)^2=0.001520xx10^6=1520 `
` rArr=Z-1=38.98 `
`=39.98=40 `
`i.e.,It is (Zr).`
` (b) (3xx10^8)/(146xx10^-12xx25xx10^14)=(Z-1)^2 `
` or, (Z-1)^2=0.0007594xx10^4 `
` or Z-1=27.5559 `
` or Z=28.5589=29 `
` i.e.,it is (Zn). `
`(c) (3xx10^8)/(158xx10^-12xx25xx10^4) =(Z-1)^2 `
` or, (Z-1)^2=0.0007594xx10^4 `
` or, Z-1=27.5559 `
` or, Z=28.5589=29. i.e.,It is (Cu). `
` (d) (3xx10^8)/(198xx10^-12xx25xx10^4)=(Z-1)^2 `
` or, (Z-1)^2=0.000606xx10^4 `
` or, Z-1=24.61612 `
` or, Z=25.6162=26. `
` i.e.,it is (Fe). `