engineering chemistry MCQ #990

The wavelength of a spectral line is given by 1 / λ = R(1 / n₁² - 1 / n₂²). What is the wavelength of the first line of the Balmer series?

engineering chemistry MCQ #990

  1. Question 1

    Q1. The wavelength of a spectral line is given by 1 / λ = R(1 / n₁² - 1 / n₂²). What is the wavelength of the first line of the Balmer series?

    • A) 6563 Å
    • B) 4861 Å
    • C) 4341 Å
    • D) 4102 Å

    Answer: 6563 Å

    Explanation: For the first line of the Balmer series, n₁ = 2, n₂ = 3. Using 1 / λ = R(1 / 2² - 1 / 3²), we get λ = 6563 Å.