Covalent Bonds

Objective Describe molecular bonds Draw e- dot structures for covalent compounds

Molecular Compounds Covalent bond: when 2 non-metals share e- Forms a covalent compound or molecular compound (also called a molecule)

Molecular Compounds Properties: Low melting and boiling points due to weak bond (much weaker than ionic) Mostly liquids, gases at room temp Weak conductors of electricity Diatomic molecule: 2 of same atom share e- 7 diatomic molecules: H2, Cl2, Br2, F2, I2, N2, O2

Octet Rule Covalent bonds form when each non-metal atom shares e- in order to attain e- config. of a noble gas (8 electrons) H: to act like He it only needs 2 e-

Now you try… Tell your neighbor 1 property of covalent compounds. Tell you neighbor how electrons are involved in a covalent bond

Single Covalent Bonds Single bond: 1 pair of e- (2 e- ) shared Ex 1: dot structure for H2

Single Covalent Bonds Ex 2: dot structure for Cl2 e- pairs that are not shared: unpaired or unshared e-

Single Covalent Bonds Ex 3: dot structure for H2O

Single Covalent Bonds Ex 4: dot structure for NH3

Now you try… Use your periodic table to draw the dot structure for the following molecules in your notes. A) SiH4 B) F2O C) PCl3

Multiple Covalent Bonds Double bond: 2 pairs of e- (4 total e-) shared Triple bond: 3 pairs of e- (6 total e-) shared Ex 1: dot structure for O2

Multiple Covalent Bonds Ex 2: dot structure for N2

Now you try… In your notes draw the dot structure for CO2.

Coordinate Covalent Bonds Coordinate covalent bond: when 1 atom contributes both e- to a bond Ex 1: CO

Coordinate Covalent Bonds Ex 2: NH4+

Coordinate Covalent Bonds Ex 3: SO3-2

Now You Try… Draw the dot structure for SO2

Ticket Out the Door Draw the dot structure for the following molecules: 1) F2 2) CH4