chem modelsofbondingandstructure
Structure 2.3.3 - transition elements have delocalised
see 3.4.8 complex ions (HL)
see 3.1.9 variable oxidation states (HL)
see 3.1.8 characteristic properties of transition elements (HL)
given the proximity in energy between the outer occupied sublevels (ie 3d and 4s), transition elements are able to delocalise d-electrons to form metallic bonding
the attraction between the large number of delocalised electrons and the large positive charge on metal cations leads to very strong metallic bonding
the lack of a clear trend is due to:
- the ability of all transition elements to delocalise a large number of electrons
- similar ionic radii
the large number of delocalised electrons result in high electrical conductivity
challenge questions
- silver is the most electrically conductive metal but is used primarily in small amounts and only on the interior of electronic devices. suggest why this might be the case
- cost
- silver reacts with the air and tarnishes, reducing its conductivity