COVALENT BONDS

Types of bonds

o Ionic bonding results from electrostatic attractions among ions, which are formed by the transfer of one or more electrons from one atom to another.

o Covalent bonding results from sharing one or more electron pairs between two atoms.

o Metallic bonding results in a sea of electrons between two cations

o http://www.picsearch.com/info.cgi?q=ionic%20bonds&id=IHgxbdtO5lawBR9zy6jqpq1E_2Jt6okckgQmu4NAeQI

What makes a covalent bond?

Covalent bonds are formed when atoms share electrons.

Two nonmetals

If the atoms share 2 electrons a single covalent bond is formed.

If the atoms share 4 electrons a double covalent bond is formed.

If the atoms share 6 electrons a triple covalent bond is formed.

Properties

Lower melting and boiling points Molecules don’t interact much

Gases or liquids at room temp Don’t conduct electricity

No ions so no charges Flexible

Molecules move around

Naming covalent compounds

Two elements Use prefixes to tell how many atoms of

each element are present Example: Carbon Dioxide

CO2

Mono is never used for the first element

Prefixes

Number

Prefix

1 mono

2 di

3 tri

4 tetra

5 penta

6 hexa

7 hepta

8 octa

9 nona

10 deca

Writing formulas

The prefixes simply tell you the subscript for each element Example: dinitrogen tetroxide

N2O4

Mono (1 is not written)Drop the vowel ending of the prefix if the prefix ends in a vowel and the element begins with a vowel.

Covalent bonding