Explain how the wavelengths of light emitted by an atom provide information about electron energy levels?

Answer 1

We know what a wavelength is, and when we apply the term to the phenomenon of electron energy levels, something amazing happens. Let's review by looking at atomic structure for a moment and take off from there.

We know that electrons form up in orbitals and shells around an atomic nucleus. These orbitals are defined as energy levels, and an electron is said to be in a given energy level. When electrons get just the right amount of energy, they can "jump" to a higher energy level. There are places that they cannot go, but there are other places that are "just right" for an electron from that particular starting energy level. A specific quantity of energy (a quantum, perhaps) is the key to electrons changing energy levels.

If an electron is "bumped" to a higher energy level because it has "accepted" a packet of energy that is just right, it moves up to that energy level. But it cannot stay there, so it "falls back" to where it came from. In returning to its original energy level, it must "give up" the exact amount of energy that it took to move up. This specific amount of energy translates into radiated electromagnetic energy of a given wavelength or frequency. And each wavelength corresponds to a given amount of energy. Let's apply this and see what happens.

Should we consider a bunch of atoms of a given kind, they will have a specific electron structure. The electrons of these atoms "live" in given energy levels. If we excite these atoms with the right amounts or quanta of energy, the electrons that will only respond to that amount of energy will move to a higher energy level. Then the electrons will return to their original levels, giving up that wavelength of energy when they drop down. If the wavelength of electromagnetic energy is in the optical band, visible light will appear. The atoms will "glow" at a specific color associated with the wavelength of the energy that is released when those electrons return to their original energy levels.

If those atoms in our experiment are a gas and we apply sufficient voltage, the gas atoms will ionize and the gas will glow. Electrons are accepting energy quanta, are moving to higher energy levels, and are then returning to their original energy levels by releasing visible light of a given color. Electron energy levels are directly related to wavelengths of electromagnetic radiation.

Answer 2

the energy level is found by the formula E = hf, where

h = the planck constant, 6.63x10-34

f = wave frequency

to find the frequency you use v=fλ, where

λ = the wavelength of the light emmited. v= speed of light = 3x108 ms-1

this gives your frequency, multiply by plancks constant and you have your electron energy! hope this helps! Jack, London UK

Answer 3

the energy difference between the electron's state before and after the transition that produced the light

Answer 4

yes