Moderate

The series limit for the Balmer series of hydrogen spectrum occurs at 3664A. Calculate ionization energy of hydrogen atom.

Correct answer: A. 21.7 x 10^-19 J

  • A. 21.7 x 10^-19 J
  • B. 13.6 x 10^-19 J
  • C. 3.4 x 10^-19 J
  • D. 8.2 x 10^-19 J

Explanation

This is the correct answer. The series limit for the Balmer series corresponds to the transition of an electron from n = ∞ (infinity) to n = 2. The energy of this transition can be calculated using the Rydberg formula:1/λ = R * (1/n1^2 - 1/n2^2)where:λ is the wavelength of the emitted photon R is the Rydberg constant (1.097 x 10^7 m^-1) n1 and n2 are the principal quantum numbers of the initial and final energy levels, respectively For the series limit, n1 = ∞ and n2 = 2. Substituting these values into the equation, we get: 1/λ = R * (1/2^2 - 1/∞^2) = R/4 Solving for λ, we get: λ = 4/R = 364.5 nm Now, we can calculate the energy of the emitted photon using the equation: E = hc/λ where: h is Planck's constant (6.626 x 10^-34 J s) c is the speed of light (3.00 x 10^8 m/s) Substituting the values, we get: E = (6.626 x 10^-34 J s) * (3.00 x 10^8 m/s) / (364.5 x 10^-9 m) = 5.42 x 10^-19 J The ionization energy of a hydrogen atom is the energy required to remove the electron from the ground state (n = 1) to infinity. Since the energy of the electron in the ground state is -13.6 eV (or -2.18 x 10^-18 J), the ionization energy is:Ionization energy = (-13.6 eV) * (1.602 x 10^-19 J/eV) = 21.7 x 10^-19 J Therefore, the ionization energy of a hydrogen atom is 21.7 x 10^-19 J.

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