Question

Solid targets of different elements are bombarded by highly energetic electron beam. The frequency of the characteristic X-rays emitted from different targets, varies with atomic number Z as

• A. $f\propto \sqrt{Z}$
• B. $f\propto Z^2$
• C. $f\propto Z$
• D. $f\propto Z^{\frac{1}{2}}$

Answer 1

The correct option is B $f\propto Z^2$

Moseley's law is an empirical law concerning the characteristic X-rays that are emitted by an atom. The frequency of the characteristic X-rays emitted from different targets, varies with atomic number Z as-
$f\propto Z^2$

So, the answer is option (B).