ABSTRACT
As discussed in Chapter 1, in the traditional numbering system of the periodic table, the A group elements are called main groups or representative elements. Only a few metallic elements occur in nature as free metals. All seven metallic elements known to the ancients (gold, silver, copper, iron, lead, mercury, and tin) have been found in the metallic state. Metals are too reactive chemically to be found in quantity as metallic elements. Except for gold, the metallic elements are obtained principally from their naturally occurring solid compounds or ores. A major source of metals and their compounds is the Earth’s crust.
