How can I construct the "Electron Configuration" of an element?Using "the "Energy Content of Atomic Orbitals"
The Electron Configuration of any given element follows precise rules regarding the placement of electrons around the atom's nucleus. Each electron follows a path around the center of the atom, or more precisely, each electron can be said to inhabit a particular "shell" loosely understood to mean a particular "cloud" layer around the center. These are designated by the undescriptive names of s, p, d, and f, which correspond to the energy levels of electrons moving about the nucleus. The term "orbital" refers to the way a particular electron is moving within a particular shell. For the element Hydrogen, there's one electron moving about the "s" shell; that electron's designation is therefore 1s1, which means "one electron in the 1s-orbital." Helium has two electrons about the center; it's designation is 1s2, which means "two electrons in the 1s-orbital." Once we reach Lithium, its electronic configuration is 1s2 2s1, which translates to "two electrons in the 1s-orbital and one electron in the 2s-orbital." For any given element, use the following tables to determine its electronic configuration, or if you're good enough, remember which orbitals get filled first with which electrons, and you could derive the electronic configuration for any element by yourself.
Just learn that the electronic configuration is always written like this:
2,8,8,8 because it is stable at this.
If we take Lithium, the atomic number is 3 so put it in the same form but fit this in that like this:
Electronic configuration of Lithium: 2,1