Question

When the electrons in hydrogen atom jumps from the orbit with $ n=2 $ to $ n=1 $ the frequency of emitted radiation is o. If the electron jumps from the orbit with $ n=3 $ to $ n=2 $ frequency of the emitted is

• A. $ \frac{5}{27}\upsilon $
• B. $ \frac{5}{36}\upsilon $
• C. $ \frac{3}{4}\upsilon $
• D. none of the above

Answer 1

Answer: (A)

: According to Bohrs theory of hydrogen spectrum, $ \frac{1}{{{\lambda }_{1}}}=R\left( \frac{1}{n_{1}^{2}}-\frac{1}{n_{2}^{2}} \right) $ for Lyman series $ =\frac{3R}{4} $ $ \frac{1}{{{\lambda }_{2}}}=R\left( \frac{1}{n_{2}^{2}}-\frac{1}{n_{3}^{2}} \right) $ for Balmer series $ \frac{2R}{36} $ $ \therefore $ $ \frac{{{\lambda }_{1}}}{{{\lambda }_{2}}}=\frac{5R}{36}\times \frac{4}{3R}=\frac{5}{27} $ Or $ \frac{{{\upsilon }_{2}}}{{{\upsilon }_{1}}}=\frac{5}{27} $ or $ {{\upsilon }_{2}}=\frac{5}{27}{{\upsilon }_{1}}=\frac{5\upsilon }{27} $ $ \therefore $ Frequency emitted $ =\frac{5}{27}\upsilon $ .