chemical bonds gr9 and 10

Write down positively charged atom first followed by negatively charged atom with their charge.
Cross the charges without their sign to obtain subscripts.
Metal atoms are named first.
Then the name of nonmetal is added.
When there are only two elements in the formula, the name ends with -ide. Oxygen is written as oxide, hydrogen as hydride. NaCI: Sodium chloride CaF2 : Calcium fluoride
A compound can have polyatomic ions with a metal. In this name of metal atom is followed by name of polyatomic ion. MgSO4 : magnesium sulphate KOH : Potassium hydroxide
Metals of the transition elements can form ions with variable positive charges. The positive charge is indicated with a Roman numeral between brackets directly after the name of the metal. CuCl2 : copper (II) chloride CuCI : copper (I) chloride