Which ligand can form a chelate ring with a metal ion?
Chelating ligands are polydentate. Oxalate (C₂O₄₂−) is bidentate, forming a 5-membered ring, unlike unidentate ligands like F− or NH₃.
Ref: NCERT Class 12 Chemistry > Chapter 5: Coordination Compounds > Topic: Nomenclature of Coordination Compounds