A spectral line of the Paschen series of hydrogen is observed at a wavelength of
CHEMISTRY · Subjective · CBSE · Chemistry · Structure of Atom · Structure of Atom
Problem
A spectral line of the Paschen series of hydrogen is observed at a wavelength of 1875nm.
(a) Show, by suitable calculation, the principal quantum number of the initial orbit from which the electron jumped to reach the Paschen series limit nf=3.
(b) Compute the energy of the emitted photon in electron-volt.
(c) If the entire photon momentum is transferred to the hydrogen atom (mass 1.67×10−27kg), calculate the recoil kinetic energy acquired by the atom. Express your answer in eV and comment on how it compares with the photon energy.