Electron shell

In atomic physics, an electron shell is a group of atomic orbitals with the same value of the principal quantum number n.

Related Topics:
Atomic physics - Atomic orbital - Principal quantum number

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It can be shown that the number of electrons that can reside in a shell is equal to 2n^2.

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Why would that be? Interest in this question and the parallels to the harmonics of guitar strings was one of the lines of questioning that led to the concept of electrons being existing in a dual wave/particle form.

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The existence of electron shells was first observed experimentally in Henry Moseley's X-ray absorption studies. He labelled them with the letters K, L, M, etc. These letters were later found to correspond to the n-values 1, 2, 3, etc. They are used in the spectroscopic Siegbahn notation.

Related Topics:
Henry Moseley - X-ray - Siegbahn notation

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The name originates from the Bohr model, in which groups of electrons were believed to orbit the nucleus at certain distances, so that their orbits formed "shells".

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