This document provides information about chemical formulas including the valencies and charges of common elements like hydrogen, oxygen, sodium, chloride, aluminum, oxide, calcium, copper, nitrate, and sulfur. It lists the symbols, charges, and chemical formulas for compounds formed from these elements, such as H2O for water, NaCl for sodium chloride, Al2O3 for aluminum oxide, and CaO2 for calcium oxide. It also gives properties of sulfur such as its atomic number, number of protons, electrons, and electron configuration.