Alfred Werner's Coordination Theory

Alfred Werner's Coordination Theory explains how certain metal compounds are structured. He proposed that metals, especially transition metals, form central atoms surrounded by molecules or ions called ligands. These ligands attach to the metal in specific arrangements, creating coordination complexes. Werner's theory introduced the idea of primary and secondary valencies (now called oxidation state and coordination number), helping to understand the different ways these complexes form. This theory clarified how metals bond with other molecules, influencing their chemical behavior and properties, and laid the foundation for modern inorganic chemistry.