Covalent Bonding (Molecular Compounds)

I. Characteristics of Molecular Compounds A. Compounds result from the sharing of electrons B. Lower melting points, and lower boiling points than ionic.

C. Exist at room temperature and pressure as solids, liquids or gases D. They do not conduct electricity in solution nor as liquids.

E. Solubility varies, most are insoluble in water. F. Collectively called “molecules”.

G. Bonding occurs between two or more nonmetals. H. Bonds are weaker than ionic bonds, but stronger than metallic bonds.

II. Naming / Writing Molecular Compounds A.Naming 1. use prefixes to represent the represent the number of atoms number of atoms of each element of each element Number of Atoms Prefix 1mono- 2di- 3tri- 4tetra- 5penta- 6hexa- 7hepta- 8octa- 9nona- 10deca-

2. never use mono- in front of 2. never use mono- in front of the first element the first element 3. second element ends with 3. second element ends with -ide -ide example: CO 2 = carbon dioxide example: CO 2 = carbon dioxide N 2 O 5 = dinitrogen N 2 O 5 = dinitrogen pentoxide pentoxide

B.Writing formulas 1. the prefix represents the # of atoms of the element (therefore the subscript) 1. the prefix represents the # of atoms of the element (therefore the subscript) 2. NO charges involved!! 2. NO charges involved!! example: carbon tetrabromide CBr 4