Atoms And Nuclei Question 290
Question: The wavelength of $ K_{a} $ X-rays produced by an X-ray tube is 0.76 A. Find the atomic number of the anode material of the tube?
Options:
A) 40
B) 30
C) 20
D) 10
Show Answer
Answer:
Correct Answer: A
Solution:
- $ \frac{1}{\lambda }=RZ^{2}( \frac{1}{1^{2}}-\frac{1}{2^{2}} )=\frac{3}{4}RZ^{2} $ $ or\text{ }Z^{2}=\frac{4}{3R\lambda } $ $ =\frac{4}{3\times ( 1.097\times 10^{7} )\times ( 0.76\times {{10}^{-10}} )}=1599.25 $ $ or\text{ }Z^{2}=1600\text{ }\therefore Z=40. $
