The shortest wavelength in Lyman series is 91 .2 nm . The longest wavelength of the series is

Step-by-step solution

The wavelength ( λ ) of lines is given by 1 λ = R 1 1 2 - 1 n 2 For Lyman series, the shortest wavelength is for n = ∞ and longest is for n = 2 . ∴ 1 λ s = R 1 1 2 … ( i ) 1 λ L = R 1 1 - 1 2 2 = 3 4 R ...(ii) Dividing Eq.(ii) by Eq. (i) , we get λ L λ s = 4 3 Given, λ s = 91.2 nm ⇒ λ L = 91.2 × 4 3 = 121.6 nm