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# Absorption and emission

Using shell model diagram to relate absorption to emission. Derives relationship between emitted photon and energy levels, the Balmer-Rydberg equation. Created by Jay.

## Want to join the conversation?

• Can we replace 'mu' with f since it is actually the frequency?
• Yes, it is the same thing. The formal letter for frequency is 'nu' but f is used just as often in scientific notation
• A photon is emitted during emission. What exactly is a photon?
• Short answer: a photon is a particle of light.
Longer answer: light is energy. Sometimes we think of light as being a wave in the form of an electro-magnetic wave but other times it can be described as a particle. A photon in this case, is 1 unit of light with a variable amount of energy which depends on its frequency.
• Wait I thought the Probability model stated that you have different chances of finding the electron at different places? How do we attempt to find the radius or the wavelength unless we assume the Probability model is false?
• You are correct that the position of the electron is not precise, and is given as a probability distribution. What is precise however are the quantized energy levels and angular momentum of the electron. This comes out of the solution of Schrodinger's equation.
• At about , the speaker says that the electron at a higher energy level will eventually fall back down to its ground state. What causes the electron to fall back down and release energy in the form of a photon? Or is it some sort of random phenomenon?
• It's not random. Everything tries to attain stability and as long as the lower orbits are not filled up, the electron has a tendency to return to the ground state and in the process, it has to release the excess energy it possesses
• What exactly do we mean by 'energy levels' ?
A hydrogen atom is in possession of a single 1s2 orbital, wherein there exists a single electron. If i were to provide this electron with a certain amount of energy, as i understand it, it would move to a higher energy level, but doesn't a hydrogen atom contain only a single orbital? where does this electron actually go? does it still remain within the orbital?
• Every atom has every possible orbital, the electron configuration is simply which orbitals have electrons in the lowest energy state. If the atom gains some energy the electron can be promoted to higher energy orbitals.
• Every step is very clear. From higher level to lower level, I do understand the election releases energy. But why is the energy in the form of light? And since lights are particles, how can I imagine where the particles are from?
• Electrons can only emit energy in the form of photons.
• When an electron goes through the process of emission, can we see the light with our own eyes?
• Even dispersion of white light is an example. White light contains all seven colours of the spectrum. So it provides electrons at different energy levels with the photon that they require to jump to the next level.
• Do the concepts of absorption and emission only apply to hydrogen?
• Luckily these concepts apply to all gaseous elements and molecules. Helium, for example, will also have absorption and emission spectra