ions forming Mn2+ again. Physical properties As implied by the name, all transition metals are metals and thus conductors of electricity. In general, transition metals possess a high density and high melting points and boiling points. These properties are due to metallic bonding by delocalized d electrons, leading to cohesion which increases with the number of shared electrons. However the group 12 metals have much lower melting and boiling points since their full d subshells prevent d–d bonding, which again tends to differentiate them from the accepted transition metals. Mercury has a melting point of and is a liquid at room temperature. See also Inner transition element, a name given to any member of the f-block Main-group element, an element other than a transition metal Ligand field theory a development of crystal field theory taking covalency into account Crystal field theory a model that describes the breaking of degeneracies of electronic orbital states Post-transition metal, a metallic element to the right of the transition metals in the periodic table References Periodic table