Sodium does not exist in the form of pure sodium in nature, but in the form of various compounds, the most common of which is sodium chloride (NaCl). Sodium chloride is a common table salt and is widely used in daily life. In addition to table salt, sodium can also form a variety of compounds with other elements, such as sodium oxide (Na2), sodium sulfate (Na2SO4) and sodium carbonate (Na2CO3), etc. 1. Food industry: Sodium salt is a common additive in food processing. Sodium chloride is widely used in foods such as condiments, canned foods, meat products and bread to improve the taste of food and keep the freshness of food. 2. Glass industry: Sodium oxide is used as a flux in the glass manufacturing process to lower the melting point of glass and increase its fluidity. Sodium carbonate can also be used to prepare glass. 3. Chemical industry: Sodium hydroxide (NaOH) is an important chemical that is widely used in the manufacture of soap pulp, cellulose and detergents. Sodium chloride is also used as a raw material for the preparation of other chemicals, such as chlorine, hydrogen chloride and sodium hypochlorite. 4. Medical field: Sodium chloride solution is widely used in medicine, such as normal saline, for infusion and injection to maintain electrolyte balance in the body. In addition, sodium hydroxide is also used in the preparation of medicines and cosmetics. 5. Metallurgical field: Sodium is a metal with good reducing properties, so it is used as a reducing agent in iron smelting and metallurgy.