Locate the elements that make up the chemical formula on the periodic table. In order to write chemical formulas for transition metals, you have to know which element is the transition metal, and which element is the nonmetal. For example, if you have to write a chemical formula for manganese (IiI) oxide, locate manganese and oxygen on the periodic table. Manganese is located in group seven. Therefore, it is a transition metal. Oxygen is located in group sixteen and is a nonmetal.
Write the chemical symbol of the transition metal to the left of the chemical symbol of the nonmetal. For example, the symbol on the periodic table for manganese is Mn, and the symbol for oxygen is O. So write, Mn to the left of the O.
Determine the charge of the elements. The charge can be identified by the name of the chemical formula, or from analyzing the periodic table. For example, the name of the chemical formula is manganese (III) oxide. The (III) indicates that within this chemical formula, manganese has a charge of +3. The charge of the oxygen is -2 because elements in the sixteenth group of the periodic table generally have a charge of -2.
Write the charge of the element as a subscript on the opposite element. In order to write a chemical formula for transition metals, it is important to make sure that each of the components of the formula has the proper subscripts, because the transition metals can form many different types of compounds with the same element. Therefore, put the subscript of 2 next to the Mn, and the subscript of 3 next to the O.