Fill in the blanks. Ionic compounds are composed of and . When
writing an ionic formula, the total charge must equal the total charge
because the number of electrons must equal the number of electrons .
Always write the symbol of the first, followed by the symbol of the .
2. On the periodic table, metals are located to the of the stairstep. Nonmetals are
located to the of the stairstep. When a metal element and a nonmetal element
combine they form an compound. When metal form ions, they are
charged. Nonmetals form ions of charge. In the process of writing formulas,
the charge on an ion is written as a . Use the criss-cross method in writing
formulas for compounds. When writing formulas for and naming ionic
compounds, the name of the always comes first, followed by the name
of the . Polyatomic ions have two possible endings: and .
The two negative polyatomic ions that break this rule are and as
well as the positively charged ion.