The chemical symbol for sodium is "Na." This symbol is derived from the Latin word for sodium, which is "natrium." Sodium is an essential chemical element belonging to the alkali metals group on the periodic table and is recognized for its highly reactive nature, particularly when in contact with water. In its pure form, sodium is a soft, silvery-white metal. It is a vital element for life, playing a crucial role in various physiological processes in the human body, such as fluid balance, nerve transmission, and muscle function.