sulfidide

Sulfide refers to a chemical compound containing sulfur in its lowest oxidation state, typically -2. This commonly occurs when sulfur bonds with less electronegative elements. The most well-known sulfide is hydrogen sulfide (H₂S), a colorless gas with a characteristic rotten egg smell. Hydrogen sulfide is highly toxic and flammable. Sulfide ions (S²⁻) are also found in many ionic compounds, such as sodium sulfide (Na₂S) and iron(II) sulfide (FeS). These compounds have diverse applications, from industrial processes to pigments.

Sulfide minerals are a significant class of naturally occurring inorganic compounds. Examples include pyrite (FeS₂), also known as fool's gold, and galena (PbS), an important source of lead. The presence of sulfides can influence the geochemistry of soils and water bodies. In biological systems, some bacteria, known as sulfate-reducing bacteria, produce hydrogen sulfide as a metabolic byproduct. This process plays a role in the sulfur cycle. However, high concentrations of hydrogen sulfide can be harmful to aquatic life. The detection and removal of sulfides are important in environmental monitoring and industrial waste treatment.