Use Moseley's law with b = 1 to find the frequency of the `K_alpha` X-ray of `La(Z = 57)` if the frequency of the `K_alpha` X-ray of `Cu(Z = 29)` is known to be `1*88 xx 10^(18)` Hz.

Answer

A, B

Explanation

Using the equation, `sqrt f = a(Z - b) (b=1)` `(f_(La)/(f_(Cu) = ((Z_(La)/(Z_(Cu) - 1))^2 or f_(La) = f_(Cu) ((Z_(Lu) - 1)/(Z_Cu) - 1))^2`