1. Covalent Compounds

2. Brainstorm: What does the prefix “Co” mean? What does covalent mean?
What types of elements do you think covalent bonds form between?

3. What is a covalent compound?
Is a compound made up of two or more nonmetals that are bonded together
- the electrons are shared instead of transferred
- the have NO charges

4. Ionic vs Covalent Compounds
Electrons are transferred from one element to the other
Occurs between a metal and a nonmetal (cation and an anion)
Electrons are shared not transferred
Occurs between two or more nonmetals

5. Why share instead of transfer?
Due to electronegativity
Metals have very low electronegativity
They do not want other atoms electrons
The have a low ionization energy (meaning they do not pull hard on their own electrons)
Nonmetals have very high electronegativity
They want other atoms electrons to complete their octet
They pull very hard on their own, and other atoms electrons

6. Can you pick out the ionic vs covalent?
H2O
Na2(SO4)
MnBr2
CO2
N2O
Al(NO3)3
KCl
P2O3
NaCl
SCl2
CCl4
Li(OH)
Sr(NO2)2
BrCl5
GaN
SO2
Cs3As2 CO
H2O2
N2P3

7. How did you do? H2O Na2(SO4) MnBr2 CO2 N2O Al(NO3)3 KCl P2O3 NaCl SCl2
CCl4
Li(OH)
Sr(NO2)2
BrCl5
GaN
SO2
Cs3As2 CO
H2O2
N3P5

8. How to write covalent compound formulas
No charges to cancel out
Several compounds can have the same elements, they just occur in different ratios.
The specific amount of atoms in each compound is what makes it a specific compound
Examples:
CO NO SO
CO2 N2O SO2
CO3 S2O3
We CANNOT and DO NOT drop and swap when writing covalent compounds

9. You must know what the numerical prefixes are

10. How to write covalent compound formulas
Use the numerical prefix on the first element as its subscript
If no prefix it means one
No need to write 1’s.
Do NOT drop and swap
Use the numerical prefix on the second element as its subscript.
The prefix mono- this time means 1

11. Give it a try: Compound Name: What is the first element?
What is the numerical value of the prefix?
What is the second element?
What is the formula? *Remember do NOT drop and swap.
Hexaboron
Monosilicide
Chlorine dioxide
Dicarbon hexahydride
Phosphorous triiodide
Iodine pentafluoride

12. How to name a covalent compound:
NEVER simplify these compounds
Example: N2O4 IS NOT NO2
For the 1st element: Use a prefix for all numbers EXCEPT one and the elements name off the periodic table.
NO2 (Nitrogen does not need a prefix for this name)
N2O (Nitrogen does need the prefix di- to indicate there are two nitrogen atoms)
For the 2nd element: ALWAYS use a prefix
For the 2nd element: Change the ending of the elements name to “-ide”

13. How to name a covalent compound:
The first element you simply name and add the proper prefix if needed
The second element you name with the proper prefix
For the second element change the ending to “-ide”
Dicarbon Hexaoxide

14. Give it a try: Compound Formula: Prefix on the first element:
Name of the first element:
Prefix on the second element:
Name of the second element with -ide ending.
Name of the compound
P4S5
SeF6
Si2Br6
CH4
NF3