The `K_(alpha)` line from molybdenum (atomic number=42) has a wavelength off .7078Å. The wavelength off `K_(alpha)` line of zinc (atomic number=30) will be

Options

A. 1Å
B. 1.3872Å
C. 0.3541Å
D. 0.5Å

Answer

B

Explanation

Wavelength `lamda=0.7078`Å
Enerrgy `E=(hc)/(lamda)`
`(z^(2))/(n^(2))=(hc)/(lamda)`
`(z_(1)^(2))/(z_(2)^(2))=(lamda_(2))/(lamda_(1))`
`((42)^(2))/((30)^(2))=(lamda_(2))/(0.7078)`
`lamda=1.3873`Å