JEE Main202329 Jan 2023Morning ShiftChemistryStructure of AtomActual
The shortest wavelength of hydrogen atom in Lyman series is λ . The longest wavelength in Balmer series of He + is
Options
- A5 9 λ
- B9 λ 5
- C36 λ 5
- D5 λ 9
Correct answer
B. 9 λ 5
Step-by-step solution
For Hydrogen atom ( H ) ( Z   =   1 ) : 1 λ H = R H × 1 2 1 1 2 - 1 ∞ 2 ...(1) For He + atom ( Z   =   2 ) : 1 λ He + = R H × 2 2 × 1 2 2 - 1 3 2   =   R H   1   -   4 9   =   R H   5 9 ..(2) From (1) & (2) λ He + λ H = 9 5 λ He + = λ × 9 5 λ He + = 9 λ 5 .