An electron in an atom drops from a higher energy level to a lower one. What does the atom do?
AAbsorbs a photon of energy equal to the level difference.
BEmits a photon of energy equal to the level difference.
CLoses mass.
DSplits into two atoms.
Explanation
📌 An electron falling from a higher to lower energy state emits a photon whose energy = ΔE = E_high − E_low. This produces emission spectra. Distractor A: absorption is the reverse; C: mass essentially unchanged; D: fission not electron transitions.