1. Covalent Bonding
EQ: How are the chemical formulas and chemical names written for covalent molecules?
How do you draw VSEPR diagrams for covalent compounds? What are the names and bonding/lone pairs for each molecular shape?

2. DAY 1

3. Review of Ionic Bonding
Ionic bonds occur between a metal and a nonmetal, or between a positively charged particle and a negatively charged particle.
Ionic bonds involve a transfer of electrons.
Can you identify which of the following are joined by ionic bonds?
NaCl - K3N MgBr2
CO2 - N Al2O3

4. Covalent Compounds
Now, you will learn about another type of bond in which electrons are shared
Covalent Bonds are atoms held together by SHARING electrons between NONMETALS

5. Covalent Bonding Covalent bonds occur between two nonmetals.
A molecule is formed when two or more atoms bond covalently.
Covalent bonds involve sharing of electrons.

6. Covalent “Molecules”
A group of atoms joined together by a covalent bond is called a MOLECULE
A compound is a group of two or more elements bonded together (Ionic or Covalent).

7. Ionic vs Covalent

8. Diatomic Molecules
Certain elements occur in nature as diatomic molecules and not as single atoms (more stable as the molecule)
Examples:
H2, N2, O2,
F2, Cl2, Br2, I2
Diatomic Molecules
are bonded together
by covalent bonds.
THE SUPER 7!!!

9. Molecular Formulas
The Molecular Formula is the formula of a molecular compound
It shows how many atoms of each element a molecule contains
Example
H2O contains 3 atoms (2 atoms of H, 1 atom of O)
C2H6 contains 8 atoms (2 atoms of C, 6 atoms of H)

10. Practice
How many atoms total and of each do the following molecular compounds contain? H2 CO
CO2
NH3
C2H6O

11. Practice: True or False
All molecular compounds are composed of atoms of two or more elements.
All compounds are molecules.
Covalent compounds are composed of two or more nonmetals.
Atoms in covalent compounds exchange electrons.

12. Naming Molecular Compounds
The first element written in the formula is always written first, using the element name.
The second element is named using the root of the element and the suffix “-ide”.
Prefixes are used to indicate the number of atoms of each type that are present in the compound.
Exception: Do not use the prefix mono- for the first element
Drop the final letter of the prefix when the element name begins with a vowel

13. Table 1: Common Prefixes Used in Covalent Compounds
Number of atoms
Prefix 1
Mono- 6
Hexa- 2
Di- 7
Hepta- 3
Tri- 8
Octa- 4
Tetra- 9
Nona- 5
Penta- 10
Deca-

14. Naming Carbon dioxide CO2: ________________________________
SO2: ________________________________
S2O3: _______________________________
N2O: _______________________________
PCl5: ________________________________
Sulfur dioxide
Disulfur trioxide
Dinitrogen monoxide
Phosphorous pentachloride

15. Formula Writing Selenium hexafluoride: ___________
Disilicon hexabromide: __________
Diboron monosilicide: __________
Iodine pentafluoride: ________
Hexaboron monosilicide: ________
SeF6
Si2Br6
B2Si
IF5
B6Si

16. Covalent Compound Lewis Structures
Lewis structures show how valence electrons are arranged among atoms in a molecule.
Lewis structures show each element with 8 valence electrons (want to achieve 8 valence just like their closest noble gas)
EXCEPTIONS:
Hydrogen (H) only wants 2
Beryllium (Be) only wants 4
Boron (B) only wants 6
Shared electron pairs are covalent bonds and can be represented by two dots (:) or by a single line ( - )

17. Single, double, & triple bonds!!!F2 O2 N2

18. Completing a Lewis Structure
EXAMPLE:
CH3Cl
1. Add up available valence electrons:
C = _____
H3 = ______
Cl = _____
Total = _____
**Each atom should have 8 ve-
2. Lewis Structure MUST be symmetrical
Single bonds FIRST and fill the octet of outer atoms
Then fill octet of inner atom
5. If you run out of valence electrons then you must add bonds!

19. Completing a Lewis Structure
EXAMPLE:
NBr3
1. Add up available valence electrons:
N = _____
Br3 = ______
Total = _____
**Each atom should have 8 ve-
2. Lewis Structure MUST be symmetrical
Single bonds FIRST and fill the octet of outer atoms
Then fill octet of inner atom
5. If you run out of valence electrons then you must add bonds!

20. Learning Check CH4 2. SO3 C = H4 = ________ Total = S = O3 = ________