The transition metals are the subgroups of elements intervening between groups IIA(2) and IIIA(13) in the periodic table. They are classified separately because of the filling of their d subshell orbitals. All the transition elements are metallic, but unlike the representative metals, they are likely to be hard, brittle, and have high melting points because of the relatively small size of their atoms and the existence of some covalent binding between ions. There are exceptions, as in the case of mercury (Hg), which is a liquid. They have high electrical conductivity because of delocalization of the s electrons similar to what occurs in the alkali and alkaline-earth metals.
Most transition metals are colored and this makes some of their ionic compounds colored. The transition metals also have complex ionic structures because of the availability of d orbitals for participating in chemical bonding.
The puzzle is as follows:
N 42° AB.CDE W 083° FG.HIJ
