1, a common salt, consists of metal ions (including ammonium ions) and nonmetallic ions.

2. Acid salts are composed of metal ions, including ammonium ions, hydrogen ions, acid ions and nonmetallic ions.

3. Basic salts are composed of metal ions, including ammonium ions, hydroxide ions, acid ions and nonmetallic ions.

4. Double salts are composed of different metal ions, including ammonium ions and acid ions.

Salt expansion:

Salt is white crystalline powder or particles, odorless, salty and soluble in water. The scientific name is sodium chloride. Salt can provide a lot of sodium. For the human body, sodium plays a variety of vital roles, which can promote the formation of protein and carbohydrates.