Ne3s2

Ne3s2, often written as [Ne] 3s2, is the electron configuration associated with magnesium in its ground state. It indicates a noble-gas core of Neon (1s2 2s2 2p6) plus two electrons in the 3s orbital, for a total of 12 electrons (atomic number 12).

Magnesium is the eighth most abundant element in the Earth's crust and is a lightweight alkaline earth metal in group 2 of the periodic table. The two 3s electrons are its valence electrons and largely determine its chemistry. They are relatively easily lost, which leads to the common oxidation state of +2, forming bonds in compounds such as magnesium oxide (MgO) and magnesium chloride (MgCl2).

In chemical notation, [Ne] 3s2 is a compact representation of the same configuration; the brackets emphasize that the core matches neon’s electron configuration, while the outer shell holds the two valence electrons.

Magnesium has various applications including structural alloys (notably magnesium-aluminum alloys), electronics casings, and lightweight components in aerospace and automotive industries. It is also biologically essential: Mg2+ participates in numerous enzymatic reactions and is a central atom in chlorophyll.

Excited states or ions can modify the outer electron configuration, for example Mg+ or Mg3+; in ionized states, electrons are removed from the 3s or deeper shells depending on energy levels.