anjoner

Anjoner, or anions, are negatively charged ions in chemistry. They form when atoms gain electrons or when molecules lose protons (in acid–base reactions), resulting in a net negative charge. In ionic compounds, anions are paired with positively charged ions (cations) and together they form salts bound by electrostatic forces. In solution, anions behave as electrolytes, moving toward the anode in electrolysis and participating in various chemical processes.

Anjoner can be monatomic, such as chloride (Cl−), fluoride (F−), and cyanide (CN−), or polyatomic, such as nitrate (NO3−), sulfate (SO4^2−), carbonate (CO3^2−), and phosphate (PO4^3−). The negative charge is typically −1 for many common monoanions, but some polyatomic anions carry −2 or −3 charges. The chemistry of anions is influenced by their size, charge, and the surrounding medium, which affects reactivity, solubility, and binding behavior.

In aqueous solutions, the speciation of anions is affected by pH and the presence of other ions. For example, bicarbonate (HCO3−) and carbonate (CO3^2−) interconvert with changes in pH, and dihydrogen phosphate (H2PO4−) and hydrogen phosphate (HPO4^2−) shift with acidity. Protonation and deprotonation equilibria determine which forms predominate under given conditions.

Anjoner play key roles in biology, environmental science, and industry. They are essential nutrients (such as phosphate and nitrate in small amounts) but can also be environmental pollutants when present in excess. They are central to buffering systems, metabolism (e.g., phosphate in ATP), and various industrial processes, including electrochemistry, catalysis, and water treatment.