An energy of 13.6 eV is needed to ionize an electron from the ground state of a hydrogen atom. Selecting the longest wavelength that will work from the those given below, what wavelength is needed if a photon accomplishes this task?
A) 60 nm
B) 80 nm
C) 70 nm
D) 90 nm
E) 40 nm

Question

Quizplus · Accepted Answer

The energy of a photon is inversely proportional to its wavelength, as given by the equation E = hc/λ, where E is the energy, h is Planck's constant, c is the speed of light, and λ is the wavelength. To ionize an electron with the least amount of energy (13.6 eV), we need the longest wavelength, because longer wavelengths correspond to lower energies. Among the given options, 90 nm is the longest wavelength, making it the correct choice for achieving ionization with the minimum required energy.

An Energy of 13