The wavelength of the second line of Balmer series is given by 1 / λ = R (1 / 2² - 1 / 4²).
Q1. The wavelength of the second line of Balmer series is given by 1 / λ = R (1 / 2² - 1 / 4²).
Answer: 4861 Å
Explanation: Substitute n1 = 2, n2 = 4, and R = 1.097 × 10⁷ m⁻¹ to get 1 / λ = 1.097 × 10⁷ (1/4 - 1/16) = 0.2057 × 10⁷, λ = 4861 Å.