The wavelength of the characteristic X-ray `K_(alpha)` line emitted from Zine `(Z = 30) is 1.415 Å`. Find the wavelength of the `K_(alpha)` line emitted from molybdenum `Z = 42)`.

Explanation

According to Moseley's law, the frequency for `K` series is proportional to `V(Z- 1)^(2)`
or `(c )/(lambda) prop (Z- 1)^(2)`
`(l )/(lambda) prop k (Z- 1)^(2)` (i)
where `k` is a constant. Let `lambda`' be the wavelength of `K_(alpha)` line emitted from molybdenum, then
`(l )/(lambda') = k (Z- 1)^(2)` (ii)
Driving (i) and (ii), we get
`lambda' = ((Z- 1)/(Z - 1)) ^(2) lambda = ((30- 1)/(42 - 1)) xx 1.415 Å`
`= 0.708 Å`