A sodium ion is a positively charged particle formed when a sodium atom loses one electron. Sodium, represented by the symbol Na on the periodic table, is an alkali metal found in group 1. Sodium ions play a crucial role in various biological processes, including nerve impulse transmission and muscle contraction. In nature, sodium ions are commonly found in salt, specifically sodium chloride (table salt). They are essential for maintaining fluid balance in the body and are involved in regulating blood pressure. Sodium ions also contribute to the electrical activity of cells, making them vital for overall health.