The wavelength of `K_(alpha)` line for an element of atomic number `43 is lambda`. Then the wavelength of `K_(alpha)` line for an element of atomic number `29` is

Options

A. `(43)/(29) lambda`
B. `(42)/(28) lambda`
C. `(9)/(4) lambda`
D. `(4)/(9) lambda`

Answer

C

Explanation

`lambda prop (1)/((Z - 1)^(2)) rArr (lambda_(2))/(lambda_(1)) = ((Z_(1) - 1)/(Z_(2) - 1))^(2)`
`rArr (lambda_(2))/(lambda) = ((43 - 1)/(29 - 1))^(2) = ((42)/(28))^(2) rArr lambda_(2) = (9)/(4) lambda`.