==Bind vs bond== 
 Re the statement " ... particular way that ions and molecules bond to metal ions".  My suggestion is that chelation is not about bonding (single, double, triple and covalent ionic etc).  It is about the points of attachment.  For this reason, I had suggested the term  bind" over "bond".  EDTA is rather ionic in its bonding, cod of course involves a lot of pi-bonding (with double bond character).  So the bonding theme can get rather involved.