Final answer:
An electron emits light with a frequency directly proportional to its energy change when dropping to a lower energy level, as described by the equation E = hv. This results in specific lines in an atomic spectrum, which are characteristic of different elements due to their unique energy levels.
Step-by-step explanation:
When an electron drops to a lower energy level, it emits light that has a frequency directly proportional to the energy change of the electron. This relation is detailed by the equation E = hv, where E is the energy of the photon emitted, h is Planck's constant, and v (or f for frequency) stands for the frequency of the emitted light. This illustrates that the photon carries a certain amount of energy that is directly proportional to its frequency. The energy change (AE) of an electron as it moves down to a lower energy level results in the emission of electromagnetic radiation at a specific frequency, which according to the equation can also be related to its wavelength by c = λf, where c is the speed of light and λ is the wavelength.
The phenomenon explains why we see discrete lines when looking at an atomic spectrum, as each line corresponds to a specific energy level transition by electrons within the atom. This also means each element has a unique atomic spectrum due to its unique energy levels. The photon's wavelength is inversely proportional to its frequency, which in turn reflects the energy change experienced by the electron.