AP EAMCET202125 Aug 2021Morning ShiftChemistryStructure of AtomActual
The shortest wavelength in hydrogen spectrum approximately is
Options
- A121 ~nm
- B91.2 ~nm
- C182 ~nm
- D89.2 ~nm
Correct answer
B. 91.2 ~nm
Step-by-step solution
Sequence of series in hydrogen spectrum are Lyman series (n=1) , Balmer series (n=2) , Paschen series (n=3) , Bracket series (n=4) and Pfund series (n=5) . For Lyman series, n₁=1 For shortest wavelength in Lyman series i.e., the energy difference in two states showing transition should be maximum i.e., n₂= Using formula, 1 =R_ H [ 1 n₁^2 - 1 n₂^2 ] here aligned R_ H & = Rydberg constant 1 & =R_ H [ 1 1^2 - 1 ^2 ] 1 =R_ H & = 1 R_ H = 1 109678 & =9.117 10⁻⁶ ~cm =91.2 ~nm aligned Hence, Lyman series is a spectral ser