Sodium ion (Na⁺) is a positively charged particle formed when a sodium atom loses one electron. This process occurs because sodium has one electron in its outer shell, which it readily gives up to achieve a stable electronic configuration. Sodium ions are essential for various biological functions, including nerve impulse transmission and muscle contraction. In nature, sodium ions are commonly found in salt (sodium chloride) and play a crucial role in maintaining fluid balance in living organisms. They are also important in various industrial applications, such as in batteries and chemical manufacturing.