1. Covalent Bonds

2. Ionic Bonds Review Valence electrons are given or taken
Metals and nonmetals only! (Polyatomic ions)
Form ions (charged particles)

3. Covalent Bonds Share valence electrons
Follow octet rule—8 valence electrons
Nonmetals and nonmetals
No ions
Number of valence electrons needed is the # of bonds formed

4. Naming Covalent Compounds
Rule #1
Element with lower group number is written first
Example: Oxygen & Carbon
Phosphorus & Sulfur

5. Naming Covalent Compounds
Exception to Rule #1
When compound contains oxygen and a halogen, name of halogen is first.
Example: Oxygen & Fluorine
Bromine & Oxygen

6. Naming Covalent Compounds
Rule #2
If both elements are in same group, element with higher period number is listed first.
Example: Selenium & Sulfur
Nitrogen & Phosphorus

7. Naming Covalent Compounds
Rule #3
The second element in the name is named as if it were an anion. That is, drop the last part of the element name and add “ide”

8. Naming Covalent Compounds
Rule #4
Greek prefixes are added to each element name to indicate the number of atoms of each in the compound.

9. Naming Covalent Compounds
Greek Prefixes
Mono one
Di two
Tri three
Tetra four
Penta five

10. Naming Covalent Compounds
Greek Prefixes (cont.)
Hexa six
Hepta seven
Octa eight
Nona nine
Deca ten

11. Naming Covalent Compounds
Exception to rule #4
If compound contains one atom of the element that is written first, mono is NOT used
CO—carbon monoxide NOT monocarbon monoxide

12. Naming Covalent Compounds
Help with spelling:
When the addition of Greek prefix causes an “a” and an “o” to be adjacent to one another, the vowel at the end of the Greek prefix is usually dropped.

13. Naming Covalent Compounds
Help with spelling:
Example: nonaoxide—nonoxide
monooxide—monoxide

14. Naming Covalent Compounds
More help with spelling:
The “i” at the end of di- and tri- is NEVER dropped.

15. Practice: Name these:
NF₃
ClO₂
P₄S₁₀
CS₂
BrF₃

16. Answers: Nitrogen trifluoride Chlorine dioxide
Tetraphosphorus decasulfide
Carbon disulfide
Bromine trifluoride

17. Practice: Write formulas:
Disulfur decafluoride
Sulfur dioxide
Iodine monochloride
Antimony trichloride
Phosphorus pentafluoride

18. Answers:
S₂F₁₀
SO₂
ICl
SbCl₃
PF₅