Covalent Bonding
and Molecular Compounds
What is a molecular Molecule?
Pure substance formed from two
or more non-metals
Occur naturally and produced
synthetically
Majority of known compounds
are molecular
EXAMPLE’S OF molecular COMPOUNDS
Nitrous oxide N2O sweet smelling gas used
to relax patients (laughing
gas)
Nitrogen dioxide NO2
reddish brown toxic gas
that pollutes atmosphere
(smog)
More example’s
Molecular compounds are all around
us
Water - H20
Sugar - C12H22O11
Carbon dioxide - C02
Living organisms make thousands of
molecular compounds
what is a covalent bond?
When two non-metals share each others electrons,
resulting in a bond that holds them together
Bond is called a covalent
bond Electrons
Sharing
Forms molecules
covalent bonding
NAMING MOLECULAR COMPOUNDS
Some molecular compounds have common names:
water H20, nitric oxide NO
Names of molecular compounds include prefixes to
indicate how many atoms of each element are present
naming molecular
compounds
Example: dinitrogen pentoxide N2O5 tells
us there are two nitrogen atoms and five
oxygen atoms
If there is only one atom of the first
element, the prefix “mono” is omitted
Name of the last element ends in “ide”
LET’S PRACTICE!
Name the following molecules:
a) SF2
b) PCl5
c) NH3
Sulfur difluoride
Phosphorus pentachloride
Ammonia
d) N2H4 Dinitrogen tetrahydride
e) H2S
Dihydrogen monosulfide
WRITING CHEMICAL FORMULAS
Prefixes in the name become the subscripts in the
formula
Example: sulfur dioxide is SO2
LET’S PRACTICE!
What is the chemical formula for carbon
dioxide?
What is the chemical formula for carbon
monoxide?
What is the chemical formula for carbon
trioxide?
What is the chemical formula for
dinitrogen pentaoxide?
N2O5
CO2
CO
CO3
diatomic molecules
Molecule consisting of only two atoms of either the
same elements..........HON 17
let’s compare
Ionic Bonding
Covalent Bonding
Makes compounds
Makes molecules
Bond btw metal and
non-metal
Bond btw two nonmetals
Transfer of electrons
Sharing of electrons
Neutral
Neutral
Weak bond
Strong bond
Example: NaCl
Example: H2O