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. Naming1. use prefixes to

represent the number of atoms of each element

Number of Atoms

Prefix

1 mono-

2 di-

3 tri-

4 tetra-

5 penta-

6 hexa-

7 hepta-

8 octa-

9 nona-

10 deca-

2. never use mono- in front of the first element 3. second element ends with -ide example: CO2 = carbon dioxide

N2O5 = dinitrogen

pentoxide

B. Writing formulas 1. the prefix represents the #

of atoms of the element (therefore the

subscript) 2. NO charges involved!!example: carbon tetrabromide

CBr4