Bromide ions are negatively charged ions formed when bromine, a chemical element with the symbol Br, gains an electron. They are commonly found in various compounds, such as sodium bromide and potassium bromide, and play important roles in both natural and industrial processes. In nature, bromide ions can be found in seawater and mineral deposits. They are used in applications like water purification, photography, and as sedatives in medicine. Due to their properties, bromide ions can also be involved in chemical reactions, contributing to the formation of other compounds.