Sodium chloride is the main component of table salt and rock salt. It is an ionic compound and is colorless and transparent cubic crystals. Sodium oxide is abundantly present in seawater and natural salt lakes, and can be used to produce chlorine gas, hydrogen, hydrochloric acid, sodium hydroxide, chlorates, hypochlorites, bleaching powder and metallic sodium, etc., making it an important chemical raw material. Chemicalbook can be used for food seasoning and preserving fish, meat and vegetables, as well as for making soap from salt precipitation and tanning leather. Highly refined sodium chloride can be used to make physiological saline, which is used in clinical treatment and physiological experiments, such as cases of sodium loss, water loss, and blood loss. Sodium chloride can be produced by concentrating and crystallizing seawater, natural salt lakes or salt wells.