F⁻ is the chemical symbol for the fluoride ion, which is formed when a fluorine atom gains an extra electron. This negatively charged ion is commonly found in nature and is known for its role in dental health, as it helps to strengthen tooth enamel and prevent cavities. Fluoride ions are often added to drinking water and dental products like toothpaste to promote oral hygiene. Additionally, fluoride is used in various industrial applications, including the production of fluorinated compounds and in the manufacturing of certain types of glass.