Electrons in a certain laser make transitions from a metastable state to the ground state.Initially there are 6*10²⁰ atoms in the metastable state and 2 * 10²⁰ atoms in the ground state.The number of photons that can be produced in a single burst is about: A)2 * 10²⁰ B)3 *10²⁰ C)4 * 10²⁰ D)6 *10²⁰ E)8 * 10²⁰

Question

Quizplus · Accepted Answer

The electrons in the metastable state make transitions to the ground state, emitting photons in the process. Each transition corresponds to the emission of a single photon. The number of photons emitted is equal to the difference in population between the metastable state and the ground state. Initial population in metastable state = 6 F1F1F1S1F1F1F10 10²⁰ atoms Initial population in ground state = 2 F1F1F1S1F1F1F10 10²⁰ atoms Number of photons emitted = (6 - 2) F1F1F1S1F1F1F10 10²⁰ = 4 F1F1F1S1F1F1F10 10²⁰. Therefore, the best choice is C.

Electrons in a Certain Laser Make Transitions from a Metastable