The term family connotes connections, bonds, and similarities. While a biological family is bonded through genetic, physical, and emotional similarities, its members each possess their own unique traits and characteristics. Likewise, the families, or groups, of the periodic table contain elements that share chemical and physical similarities, but are at the same time distinctive and individual.

            The elements contained in groups 3 through 12, from the III A family to the II B family, are called transition metals. Like all metals, transition metals conduct heat and electricity and are malleable and ductile. These differ from other metals, however, in that their valence electrons are present in more than one shell; therefore they do not have definite and constant oxidation numbers. This makes transition metals excellent catalysts. Since the s sublevel has less energy than the d sublevel, it will fill with electrons before the d sub-orbital does. Transition elements have full s sub-orbitals and incomplete d sub-orbitals; this identical arrangement of outer electrons explains why all transition metals are so similar. The electron arrangements of the d sub-orbitals differ as you move across the table. When all electrons in the d sub-orbital are paired, compounds of the transition metals are diamagnetic, not attracted by a magnetic field. Otherwise, compounds are paramagnetic, attracted by a magnetic field. The varying oxidation states that result from this make transition metals useful catalysts.

            The elements of Group I have one electron in their outer shell. This group is divided into two sub-groups, group I A and I B. Group I A are the alkali metals, while Group I B contains the transition metals gold, silver, and copper. The elements of Group II have two electrons in their outer shell. This group is also divided into two sub-groups, group I B and II B. Group I B are the alkaline earth metals, while Group II B contains the transition metals cadmium, zinc, and mercury.

GOLD