Atomic Structure

Neon is a noble gas with a stable electron configuration. Since all electrons are paired, the magnetic moment of atomic neon is zero due to the cancellation of the magnetic effects of individual electron spins.

The energy difference between the fifth and ground energy levels in a hydrogen atom is responsible for the emission of a photon.
The velocity of the atom after the emission can be found using conservation of momentum.
The momentum of the photon emitted is equal to the change in momentum of the atom: where is the wavelength corresponding to the energy difference between the levels. Using energy conservation and the Rydberg formula, we get: where is Planck's constant, is the Rydberg constant, and is the mass of the electron.
Thus, the correct answer is (a).

The frequency of the emitted radiation when an electron in a hydrogen atom transitions between energy levels is given by the Rydberg formula: The frequency is related to the energy by: Thus, for the transition from to , the frequency is twice the frequency for the to transition.
Given the frequency for to is , the frequency for to transition is .
Thus, the correct answer is (a).