•Coordinationnumber:thenumberofdonoratomssurroundingthecentralmetalatominacomplexion.Commonly,itis2,4,5or6Formonodentate:[Cu(NH3)4]SO4,[Fe(CN)6]4Coordinationnumber=ligandnumberForbidentateorpolydentate：Coordinationnumber≠ligandnumbere.g.[Cu(en)2]SO4(en=H2N-CH2-CH2-NH2)Coordinationnumber=4≠2 Charg...