NAME:___________________________________
DATE:_____________________
PERIOD:_____
#:_____
Covalent Bonding & Molecular Compounds Notes
Key Terms
A Chemical
Formula
_____ A neutral group of atoms that are held together by
covalent bonds.
B
Diatomic
Molecule
_____ A chemical compound whose simplest units are
molecules.
C
Molecular
Compound
_____ Shows the relative types and numbers of atoms by
using atomic symbols and numerical subscripts.
D Molecular
Formula
_____ Shows the types and numbers of atoms combined in a
single molecule of a molecular compound.
E
_____ A molecule containing only two atoms.
Molecule
Formation of a Covalent Bond
**Analyze image to the right to
describe what happens to
potential energy as bonds form.
_____________________________
_____________________________
_____________________________
_____________________________
_____________________________
Video Notes:
Covalent Bonding & Molecular Compounds Notes
Characteristics of Covalent Bonds
Bond length is ____________________________________________________________
Bond energy is ___________________________________________________________
**As bond length decreases, bond energy ________________. As bond length
increases, bond energy ________________.
Therefore, the relationship between bond length and bond energy is a(n)
_______________ relationship.
Octet Rule
The octet rule states that chemical compounds _______________________________________
______________________________________________________________________________
Exceptions to the Octet Rule:
Covalent Bonding & Molecular Compounds Notes
Exceptions to the Octet Rule
1. Some elements are satisfied with fewer than 8 valence electrons:
a. Hydrogen: __________________________________________
b. Beryllium: __________________________________________
c. Boron: _____________________________________________
2. Some elements can be surrounded by more than eight electrons when they bind to
highly electronegative atoms (F, O, Cl). Called an ______________________________.
Lewis Structures
A method for using electron-dot notation to represent molecules.
Dots: __________________________________________________________
Dashes: ________________________________________________________
A shared pair of dots (electrons) is replaced with a __________.
Steps for Drawing Lewis Structures
1. Determine the type and number of atoms in the molecule. Obtain the correct element
cards from the bag.
CH3I example:
2. Write the electron-dot notation for each type of atom and then determine the total
number of valence electrons. Use different colored beads to represent the valence
electrons around each type of atom.
CH3I example:
3. Place atom with most open spaces (single electrons) in the middle. Arrange cards
around the central atom.
_____________ will always be in the center if present.
_____________ & _____________ will never be centrally located.
CH3I example:
Covalent Bonding & Molecular Compounds Notes
4. Make sure each element (except hydrogen) is surrounded by 8 valence electrons.
Replace bonding electron pairs (beads) with straw sticks.
CH3I example:
If not all atoms are surrounded by 8 valence electrons, move electron pairs to form
double or triple bonds. __________ & __________ will never form double or triple
bonds.
5. Check work by counting number of valence electrons.
Should have same number of electrons as in step ____.
CH3I example:
Double Bond Example – CH2O
Triple Bond Example – CO
Single vs. Multiple Bonds
Single bonds _____________________________________________________________
Multiple bonds ___________________________________________________________
Bond Type
Double
Triple
Bond Length
Bond Energy