Final answer:
The oxalate ion is a bidentate ligand, capable of forming two coordinate bonds with a central metal ion.
Step-by-step explanation:
The oxalate ion is a bidentate ligand, which means it has two donor atoms capable of forming coordinate bonds with a central metal ion. This ion can attach to the metal ion at two different points, like a pair of headphones snugging around the ion. Bidentate ligands, like oxalate, are distinct from monodentate ligands, which bind through only one donor atom, and polydentate ligands (such as tridentate, tetradentate, etc.), which have more than two donor atoms. The oxalate ion is often involved in forming coordination complexes due to its ability to occupy adjacent positions on the central metal ion.