silverbromide

Silver bromide, with the chemical formula AgBr, is an inorganic salt formed from silver ions and bromide. It appears as a pale yellow to off-white solid and is sparingly soluble in water, with a solubility product near 5 × 10^-13 at room temperature. In solution it can form complex ions with ammonia, such as [Ag(NH3)2]+, which increases its solubility under concentrated conditions.

Silver bromide is typically prepared by precipitating AgBr from solutions of silver salts (for example, silver nitrate) and bromide sources (such as potassium bromide), followed by washing and drying. It is a commonly encountered halide in photographic chemistry and is often used in photographic emulsions alongside other silver halides.

In photography, silver bromide is valued for its light sensitivity. When exposed to light, tiny changes occur within the AgBr crystals, forming a latent image that is not initially visible. During chemical development, exposed crystals are reduced to metallic silver, producing the visible image, while bromide ions are regenerated in the emulsion. This property made AgBr a foundational component of traditional black-and-white photography and film-based imaging.

Beyond conventional photography, silver bromide is used in some radiographic films and in archival photographic processes. It remains of interest in materials science as a model system for studying light-induced redox reactions and the chemistry of silver halides.