Sodium belongs to the alkali metal family on the periodic table. Alkali metals have a single valence electron, making them very reactive elements. Sodium is an electron donor and readily forms compounds with nonmetals, which are generally electron acceptors.
Sodium, like the elements in the alkali metal family, is not found in its elemental state in nature. The alkali metals donate their one electron in the outermost energy level to other elements such as nonmetals, especially the halogen family of elements.
Once sodium donates its electron to another atom, it becomes a positive ion. The other element becomes a negative ion. Positive and negative substances attract; therefore, sodium and the negatively charged atom come together to form an ionic compound. Table salt, which has the chemical name sodium chloride, is a common compound consisting of one atom of sodium bonded to one atom of chlorine.