Br⁻ is the chemical symbol for the bromide ion, which is formed when bromine, a halogen element, gains an extra electron. This gives the ion a negative charge, making it an anion. Bromide ions are commonly found in various compounds, such as salts, and play important roles in biological and chemical processes. Bromide ions are often used in pharmaceuticals, photography, and water treatment. They can help regulate pH levels and act as disinfectants. In nature, bromide is present in seawater and can be found in certain minerals, contributing to the overall balance of bromine in the environment.