Chapter+5+Molecules+and+compounds+CONT>>>


 * compounds have constant composition
 * **molecular elements:** consist of diatomic molecules HOFBrINCl
 * **Molecular compounds**: two or more nonmetals
 * **ionic compounds**: compounds formed from a metal and one or more nonmetals.

**Nomenclature:**
If the metal forms one type of ion only: name of cation (metal) and base name of anion (nonmetal) + ide If the metal forms more than one type of ion: name of cation (metal), charge of the cation in roman numerals in parentheses and the base name of the anion + ide
 * //For Ionic compounds//**(metal and nonmetal):

NEVER use the MONO prefix for the first part!!!
 * //For Molecular compounds//** (nonmetals only):prefix name of 1st element prefix base name of 2nd element +ide

If it is composed of two elements: hydro, base name of nonmetal + ic, acid If it contains oxygen and ends in ate: use the base name of oxyanion + ic acid If it contains oxygen and ends in ite: use the base name of oxyanion + ous acid
 * //Acids//**(Hydrogen and one or more nonmetals:

FORMULA MASS
Formula mass=(# atoms of 1st element in a chemical formula x atomic mass of 1st element) + (# of atoms in 2nd element x atomic mass of 2nd element)+... EX formula mass of water is 2(1.01 amu) + 16.00 amu=18.02 amu CHAPTER SIX CHEMICAL COMPOSITION>>>>