AP Chem term (Ch. 20) | Definition |
complex ion | a charged species consisting of a metal ion surrounded by ligands. |
lanthanide contraction | the decrease in the atomic radii of the lanthanide series elements, going from left to right on the periodic table. |
lanthanide series | a group of fourteen elements following lanthanum in the periodic table, in which the 4f orbitals are being filled. |
coordination compound | a compound composed of a complex ion and counter ions sufficient to give no net charge. |
counterions | anions or cations that balance the charge on the complex ion in a coordination compound. |
oxidation states | a concept that provides a way to keep track of electrons in oxidation-reduction reactions according to certain rules. |
coordination number | the number of bonds formed between the metal ion and the ligands in a complex ion. |
ligand | a neutral molecule or ion having a lone pair of electrons that can be used to form a bond to a metal ion; a Lewis base. |
coordinate covalent bond | a metal-ligand bond resulting from the interaction of a Lewis base (the ligand) and a Lewis acid (the metal ion). |
monodentate (unidentate) ligand | a ligand that can form one bond to a metal ion. |
chelating ligand (chelate) | a ligand having more than one atom with a lone pair that can be used to bond to a metal ion. |
bidentate ligand | a ligand that can form two bonds to a metal ion. |
isomers | species with the same formula but different properties. |
structural isomerism | isomerism in which the isomers contain the same atoms but one or more bonds differ. |
stereoisomerism | isomerism in which all the bonds in the isomers are the same but the spatial arrangements of the atoms are different. |
coordination isomerism | isomerism in a coordination compound in which the composition of the coordination sphere of the metal ion varies. |
linkage isomerism | isomerism involving a complex ion where the ligands are all the same but the point of attachment of at least one of the ligands differs. |
geometrical (cis-trans) isomerism | isomerism in which atoms or groups of atoms can assume different positions around a rigid ring or bond. |
optical isomerism | isomerism in which the isomers have opposite effects on plane-polarized light. |
chirality | the quality of having nonsuperimposable mirror images. |
enantiomers | isomers that are nonsuperimposable mirror images of each other. |