What happens when the electron in a hydrogen atom flips its direction of spin from parallel to antiparallel to that of the proton? A) Nothing. This event is a forbidden transition that never occurs. B) The atom emits a photon of 656.3-nm wavelength (H _$\alpha$ ) in the red region of the spectrum. C) The atom emits a photon of 21-cm wavelength in the radio region of the spectrum. D) The atom emits a photon of 121.5-nm wavelength (L _$\alpha$ ) in the UV region of the spectrum.

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Quizplus · Accepted Answer

This event describes the hyperfine transition in hydrogen, where the electron flips its spin relative to the proton, resulting in the emission of a 21-cm wavelength photon in the radio spectrum. This is a fundamental process in astronomy for detecting interstellar hydrogen clouds.

What Happens When the Electron in a Hydrogen Atom Flips α\alphaα

What Happens When the Electron in a Hydrogen Atom Flips $\alpha$