Topic overview

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Sodium commonly occurs as sodium chloride in seawater and rock salt, and is isolated industrially by electrolysis of molten sodium chloride and calcium chloride. The metal is soft and low-density, and is stored under kerosene to limit oxidation. Its reaction with water produces sodium hydroxide and hydrogen, while combustion in air can yield different oxides depending on oxygen availability. Sodium’s intense yellow flame is a useful identifying feature. The topic also surveys compounds such as sodium hydroxide, sodium carbonate, and sodium bicarbonate, linking them to manufacturing and everyday applications. Sodium ions have an important role in extracellular fluid, while analytical methods can detect or quantify them. These properties and uses provide context for the metal’s practical applications and hazards.