Question

If R is the Rydberg Constant in $c{m}^{-1}$, then hydrogen atom does not emit any radiation of wavelength in the range of

• A. $\frac{1}{R}to\frac{4}{3R}cm$
• B. $\frac{7}{5R}to\frac{19}{5R}cm$
• C. $\frac{4}{R}to\frac{36}{5R}cm$
• D. $\frac{9}{R}to\frac{144}{7R}cm$

Answer 1

The correct option is B $\frac{7}{5R}to\frac{19}{5R}cm$

Option a belongs to Lyman series where transition is from first orbit to any other orbits upto infinity.
Option c belongs to Balman series where transition is from second orbit to any other orbits upto infinity.
Option d belongs to Paschen series where transition is from third orbit to any other orbits upto infinity.

Option (b) does not belong to any transition series. Therefore, hydrogen atom does not emit any radiation of wavelength in this range.