Covalent Bonding
Lesson1 :Covalent Bonding
 Covalent bonds: atoms held together by sharing




electrons.
Molecules: neutral group of atoms joined together by
covalent bonds.
Diatomic molecule: molecule consisting of 2 atoms.
Remember them: F2, Cl2, I2, Br2, H2, N2, O2
Molecules tend to have lower melting and boiling
points than ionic compounds.
YouTube - Making Molecules with Atoms
Molecular Formula
 Shows how many atoms of each element a molecule
contains.
 Naming binary molecular compounds
 Composed of two nonmetals; often combine in more
than one way. Ex. CO and CO2
 Prefixes are used to name binary molecular compounds.
Prefix
Mono-
Di-
Tri-
Tetra-
Penta-
Hexa-
Hepta-
Octa-
Nona-
Deca-
Number
1
2
3
4
5
6
7
8
9
10
Binary Compounds
Containing Two Nonmetals
To name these compounds:
1) give the name of the less electronegative element first
with the Greek prefix indicating the number of atoms
of that element present
2) After give the name of the more electronegative nonmetal with the Greek prefix indicating the number of
atoms of that element present and with its ending
replaced by the suffix –ide.
3) Do not use the prefix mono- if required for the first
element.
Binary Molecular Compounds
N2O
N2O3
N2O5
dinitrogen monoxide
dinitrogen trioxide
dinitrogen pentoxide
ICl
ICl3
iodine monochloride
iodine trichloride
SO2
sulfur dioxide
SO3
sulfur trioxide
YouTube - Naming molecular compounds
Binary Molecular Compounds
Containing Two Nonmetals
As2S3
1. ________________
SO2
2. ________________
diarsenic trisulfide
sulfur dioxide
P2O5
diphosphorus pentoxide
____________________
CO2
4. ________________
carbon dioxide
3.
5.
N2O5
dinitrogen pentoxide
____________________
6.
H2O
dihydrogen monoxide
____________________
Naming Binary Compounds
Binary Compound?
Yes
Metal Present?
No
Molecule
Use Greek
Prefixes
Yes
Does the metal form
more than one cation?
No
Ionic compound (cation has
one charge only)
Use the element
name for the cation.
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 98
Yes
Ionic compound (cation has more
than one charge) Determine the
Charge of the cation; use a Roman
numeral after the cation name.
Classwork #1:
Do handout “Naming
Molecules”