Nuclear Physics And Radioactivity Question 81
Question: The wavelength Ka X-rays produced by an X-ray tube is 0.76 Å. The atomic number of anticathode material is
Options:
A) 82
B) 41
C) 20
D) 10
Show Answer
Answer:
Correct Answer: B
Solution:
For $ {K_{\alpha }} $ X-ray line $ \frac{1}{{\lambda_{\alpha }}}=R{{(Z-1)}^{2}}[ \frac{1}{1^{2}}-\frac{1}{2^{2}} ]=\frac{3R}{4}{{(Z-1)}^{2}} $ On putting the given values $ \frac{1}{0.76\times {{10}^{-10}}}=\frac{3}{4}\times 1.09\times 10^{7}{{(Z-1)}^{2}} $
Þ $ {{(Z-1)}^{2}}\approx 1600 $
Þ $ Z-1=40 $
Þ $ Z=41 $
BETA
