When the electron in a hydrogen atom moves from n = 4 to n = 2, light with a wavelength of __________ nm is emitted.
A)93.8
B)434
C)410
D)657
E)486

Question

Quizplus · Accepted Answer

The energy of the emitted photon can be found using the formula E=hc/λ, where E is the energy, h is Planck's constant, c is the speed of light, and λ is the wavelength of the light emitted. The energy lost by the electron is equal to the energy gained by the emitted photon, which is given by E = (-13.6 eV) [(1/nf^2) - (1/ni^2)]. Substituting nf=2 and ni=4 gives an energy change of ΔE=3.4 eV, which corresponds to a wavelength of λ = hc/ΔE = 486 nm. Therefore, the best answer choice is E.

When the Electron in a Hydrogen Atom Moves from N