determining if polydentate

[Rebecca Epner 4A]

How do you determine if a ligand can be polydentate?
For example, question 9C.5 asks to determine if the following ligand is polydentate, and if so, give the maximum number of places on the ligand that can bind simultaneously to a single metal center.
HN(CH2CH2NH2)2

[McKenna_4A]

Polydentate refers to a ligand forming multiple bonds with the central atom. If a Ligand has multiple sites that can bond (Polar regions, lone pairs etc..) it is said to be polydentate

[Ryan Chang 1C]

Correct me if I'm wrong but I believe HN(CH2CH2NH2)2 is tridentate because the central atom would be nitrogen, which is attached to a hydrogen and 2 CH2CH2NH2 molecules.

[Chantel_2I]

This molecule has three Nitrogen atoms, each with a lone pair. Each long pair can form a bond with a cation, so it is tridentate.