Naming Polydentate Coordination Compounds

[Devyn Chun 3I]

When we are naming coordination compounds, is the only way to tell if a ligand is polydentate is to visualize it with Lewis structures? If yes, is a ligand polydentate if it has a lone pair of electrons or another place it can bind to the central atom?

[Chem_Mod]

You are right in that a ligand is polydentate if it has multiple lone pairs that can bind to the central atom. Be sure to consider steric hinderance as well when determining if polydentate. Lewis structures would probably be the best route, but you can also eliminate molecules that won't be polydentate if they are relatively small (such as made up of only two atoms), so that you don't draw lewis structures for every single thing you see.