A collection of atoms has 20% of the sample in a state 5.9 eV above the ground state. If these emit coherent radiation, what is the wavelength of the laser light produced? (c = 3.00 × 10⁸m/s, h = 6.626 × 10^-34 J ∙ s, 1 eV = 1.60 × 10^-19 J) A) 210 nm B) 91 nm C) 340 nm D) 34 nm

Question

Quizplus · Accepted Answer

The energy of a photon is given by E = hc/λ, where E is the energy of the photon, h is Planck's constant, c is the speed of light, and λ is the wavelength of the photon. The energy of a photon emitted when an electron falls from a higher energy state to a lower energy state is given by E = hf, where f is the frequency of the photon. The frequency of a photon is given by f = c/λ. Therefore, the wavelength of a photon emitted when an electron falls from a higher energy state to a lower energy state is given by λ = hc/E.In this problem, the energy of the photon emitted is 5.9 eV. Therefore, the wavelength of the photon emitted is:λ = hc/E = (6.626 × 10^-34 J s)(3.00 × 10^8 m/s)/(5.9 eV)(1.60 × 10^-19 J/eV) = 210 nmTherefore, the correct answer is A.

A Collection of Atoms Has 20% of the Sample in a State