ABSTRACT
Carbon is nonmetal and lead is a typical metal, while silicon and germanium exhibit semiconducting properties. Compounds with hydrogen are stable and common for carbon, but the number of such compounds for silicon and germanium becomes limited, and for lead, only one unstable compound of that type is known. The chemistry of the divalent state is more important for heavier elements and the basicity of oxides increases from carbon to lead. Carbon forms a great number of compounds with different oxidation states. The characteristic feature of carbon is significant stability in both the +4 and -4 valence state compounds. Only the potentials of those compounds of carbon that are traditionally grouped with inorganic substances. The electrode reactions of silicon species are slow under normal conditions, which may follow from the fact that the bonds of silicon with other atoms are quite strong.
