Bromide anions are negatively charged ions formed when bromine, a halogen element, gains an electron. They are represented by the chemical symbol Br-. Bromide is commonly found in nature, often in the form of salts, such as sodium bromide or potassium bromide, which dissolve in water to release bromide ions. Bromide anions play important roles in various chemical processes and applications. They are used in photography, water treatment, and as a sedative in medicine. Additionally, bromide ions can be involved in the formation of brominated compounds, which are used in flame retardants and other industrial applications.