All right. Because Russia is rich in salt, it has a rich coastline and rich sea salt. Sea salt is nutritious, cheap and of high quality, so it is very good. China is also rich in sea salt. The quality of Russian sea salt is similar to that of China sea salt, and it is very popular. Chemically, salt refers to a class of compounds in which metal ions or ammonium ions (NH4+) are combined with acidic ions or nonmetallic ions, such as calcium sulfate, copper chloride and sodium acetate. Generally speaking, salt is the product of double decomposition reaction, such as sulfuric acid and sodium hydroxide to produce sodium sulfate and water, and other reactions can also produce salt, such as displacement reaction.