Transition Elements

1. ligands

1.1. a ligand is a molecule or ion with one or more lone pair s of electrons available to donate to a transition element

1.2. ligand exchange can be described in terms of competing equilibria

1.2.1. ligands can be exchanged for other ligands in a complex, which may result in a change of color

1.3. bidentate ligands can form two co-ordinate bonds from an ion or molecule to the transition metal ion

1.4. monodentate ligands can only form one co-ordinate bond

1.5. transition elements form complexes by combining with ligands

1.5.1. ligands bond to transition metal ions by one or more co-ordinate bonds

2. stereoisomerism

2.1. geometric isomerism are complexes with the same molecular formula but different geometrical arrangements of their atoms

2.2. commonly shown by octahedral complexes

3. color of complexes

3.1. transition metal compounds are often colored because of d orbital splitting caused by ligands

3.1.1. different ligands will split the d orbitals by different amounts, resulting in different colored complexes

3.2. degenerate orbitals are orbitals that are all at the same energy level

3.3. nondegenerate orbitals are orbitals that are at slightly different energy levels

4. redox reactions

4.1. many reactions involving transition elements are redox reactions

4.2. some redox reactions are used in titrations to determine concentrations

5. physical properties

5.1. high melting points

5.2. high densities

5.3. hard and rigid

5.4. good conductors of electricity and heat

6. what is a transition element?

6.1. d-block element that forms one or more stable ions with an incomplete d subshell

7. atoms

7.1. transition elements' atoms have a filled 4s subshell, and their remaining electrons are in the 3d subshell

7.2. chromium and copper atoms are exceptions to this

8. ions

8.1. each transition element forms at least one ion with a partially filled d orbital

8.2. have variable oxidation states

8.3. when oxidized, it loses electrons from the 4s subshell the the 3d subshell, forming a positive ion

9. stability constants

9.1. the stability constant of a complex ion is the equilibrium constant for the formation of the complex ion in a solvent from its constituent ions or molecules

9.1.1. the higher the value of the stability constant, the more stable is the complex ion formed

9.2. Kstab