Chemical formula

Declares the type of atom and the relative amount of a substance that sort.
Be divided into 3:
a. Molecular formula
Declares the type and number of atoms of an oxygen molecule prepare
Example: molecular formula of water (H2O)

b. Chemical formula compound Ion
Declares the type and number of atoms that arrange a compound ion
Characteristic of compound ion is one of the composer atom compound are metal (located in front)
Example: Mg (NO3) 2; BaCl2; CuSO4; NaCl

c. Empirical formula
The formula is also called, and the type of claim is a simple comparison of the atom-atom in a compound
Example: Etuna with molecular formula C2H2 and have empirical formula CH
The formula is a chemical compound ion empirical formula
Example: salt (NaCl)