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 $=\frac{5}{27}\upsilon$ .