Octet Rule Exceptions Incomplete octets We have seen previously that for elements below atomic number 20 the octet rule states that the atoms try to achieve 8 electrons in their valence shells, so ...
Sigma Bonds Bond overlap in covalent bonds A single covalent bond is formed when two nonmetals combine Each atom that combines has an atomic orbital containing a single unpaired electron When a cov...
Factors Affecting Colour The size of the splitting energy ΔE in the d-orbitals is influenced by the following four factors: The size and type of ligands The nuclear charge and identity of the metal...
Crystal Field Theory Perception of colour Most transition metal compounds appear coloured. This is because they absorb energy corresponding to certain parts of the visible electromagnetic spectrum ...
Catalytic Properties Transition metals are often used as catalysts in the elemental form or as compounds The ability of transition metals to form more than one stable oxidation state means that the...
Complex Ions Transition element ions can form complexes which consist of a central metal ion and ligands A ligand is a molecule or ion that forms a co-ordinate bond with a transition metal by donat...
Variable Oxidation States When transition elements forms ions they lose electrons from the 4s subshell first This is because when the orbitals are occupied, the repulsion between electrons pushes t...
Transition Elements Transition metals are elements with an incomplete d-subshell or that can form at least one stable cation with an incomplete d-subshell This definition distinguishes them from d-...
Trends Across a Period Ionisation energies show periodicity – a trend across a period of the Periodic Table As could be expected from their electron configuration, the group 1 metals have a relativ...
