Define Electronic Configuration.

Electronic configuration:

• It is defined as the arrangement or distribution of electrons in various shells or orbits around the nucleus of an atom.
• Bohr and Bury explained the concept of electronic configuration.
• The orbits or shells are represented either by numbers 1, 2, 3, 4,…or letters K, L, M, N,…
• A given orbit or shell can accommodate the maximum of $2{\mathrm{n}}^2$ electrons where n represents the number of energy shells.
• The outermost or the valence shell could accommodate a maximum of 8 electrons except for the K-shell which can hold a maximum of 2 electrons in it.
• The shell just before the valence shell can hold only a maximum of 18 electrons.