1. How Atoms Interact with Each Other
Sodium chloride
Nitrogen dioxide
Carbon monoxide
Chapter 1 Activity 8
Hydrochloric acid
Calcium fluoride
How Atoms Interact with Each Other
Magnesium sulphate
Hydrogen peroxide

3. Why Do Elements Form Compounds?
to become stable
The Octet Rule:
Atoms tend to gain or lose electrons during chemical reactions so that the atoms have a filled outer energy level (usually 8 electrons).
Lose 1 electron
Gain 1 electron Na F
2 7

4. How do we show bonding between atoms?
We show bonding using:
electron-dot diagrams or
Lewis Dot Diagrams 4

5. Lewis Dot Diagrams Each dot represents a valence electron
Now practice writing the Lewis Dot for elements in the third period

6. Try this!!!
Practice determining the number of valence electrons in an atom
Practice writing the Lewis diagram for atoms 1-20. 6

7. Is it still an atom? protons = electrons THEY ARE NOW IONS!!!
Atoms are neutral-
protons = electrons
After electrons are lost or gained, they are no longer atoms.
THEY ARE NOW IONS!!!

8. Ionic Bonds Exist between a metal & nonmetal
Metals want to lose their valence electrons
And become Cations (+)
Nonmetals want to gain more valence electrons
And become Anions (-)
Why……. To become stable

9. Which elements lose and gain electrons?IA
VIIIA
IIA
IIIA
IVA VA
VIA
VIIA -4 +4 -3 -2 -1 +1 +2 +3
Which elements lose and gain electrons? 9

10. So…
A Metal and a Nonmetal get together!
But remember, they get together to get a filled outer energy level
And that is the octet rule

11. FORMATION OF IONIC BONDS
Electrons are transferred from a metal to a nonmetal
The metal becomes a cation; the nonmetal becomes an anion.
The attraction of the oppositely charged ions forms the ionic bond.

12. Naming Ionic Compounds

13. Ionic Compounds
Attraction between a metal cation (M+) and a nonmetal anion (X-)
M+ X-
Charges on ions must add up to zero!

14. Naming an Ionic Compound:
1. Write the name for the metal and nonmetal
2. Change the nonmetal ending to IDE
Ex: NaCl
sodium chloride

15. Element
Ion Name
Carbon
Nitrogen
Phosphorus
Oxygen
Sulfur
Fluorine
Chlorine
Bromine
Iodine
carbide
nitride
phosphide
oxide
sulfide
fluoride
chloride
bromide
iodide

16. Chemical Formula Chemical Name
EXAMPLES:
Chemical Formula
Chemical Name
KBr
Na2O
MgS
Ca3N2
AlF3
potassium bromide
sodium oxide
magnesium sulfide
calcium nitride
aluminum fluoride

17. Writing Ionic Compounds

18. How to Write an Ionic Formula:
1. Write down symbols
2. Determine Ionic Charges
3. Charges must cancel each other out
(equal zero)
if not, use criss-cross method to form subscripts to cancel out charges

19. KBr MgO AlN MgCl2 Na2S Chemical Name Ion Charges Chemical Formula
EXAMPLES:
Chemical Name
Ion Charges
Chemical Formula
Potassium Bromide
Magnesium Oxide
Aluminum Nitride
Magnesium Chloride
Sodium Sulfide
K+1 Br-1
charges cancel
KBr
Mg+2 O-2
charges cancel
MgO
Al+3 N-3
charges cancel
AlN
Mg+2 Cl-1
charges DON’T cancel
criss-cross
MgCl2
Na+1 S-2
charges DON’T cancel
criss-cross
Na2S

20. EXAMPLES:
Potassium Bromide
K Br charges cancel KBr
Magnesium Oxide
Mg O-2 charges cancel MgO
Aluminum Nitride
Al N-3 charges cancel AlN
Magnesium Chloride
Mg Cl charges don’t cancel, criss-cross MgCl2
Sodium Sulfide
Na S charges don’t cancel, criss-cross Na2S
Aluminum Oxide
Al O charges don’t cancel, criss-cross Al2O3

21.                                             Ionic Bonds:
One big greedy thief dog!
Ionic bonding can be best imagined as one big greedy dog steeling the other dog's bone. 

22. Lewis Dot Diagrams Ionic BondsLi F • F • Li
2 1 • F
2 7 • Li • F • Li • F • Li
by giving or taking
electrons with
other atoms.
Each atom
attempts to attain
a filled outer energy
level • F • Li +1 • F Li -1 Li 2 +1 F
2 8 -1 22

23. Count around Fluorine, there are 8 dots (8 valence electrons to make it stable)• F Li +1 -1

24. What is an Ion? A charged atom
Becomes charged after it loses or gains electrons
It has a charge because the number of protons and electrons are no longer equal Li 2 +1 F
2 8 -1 • F Li +1 -1
P=3 E= P=9 E =10

26. Bonding & Non-bonding Electrons
Bonding electrons-are the 2 electrons that form the bond between the atoms
This can be represented with a dash • F Li
Bonding electrons

27. Bonding & Non-bonding Electrons
Nonbonding electrons-are any electrons that DO NOT form the bond between the atoms.
They are in pairs (here there are 3 pairs of nonbonding electrons • F Li
Nonbonding electrons

28. Chapter 1 Activity 8
Covalent Bonding

29. What is an Ionic Bond? IONIC BONDS:
1. Give or Take (transfer) valence electrons
2. Occur between a metal & nonmetal
3. High melting points
4. Conducts electricity when in solution
EX: NaCl MgCl2

30. What is a Covalent Bond? COVALENT BONDS: 1. Share valence electrons
2. Occur between nonmetal atoms only
3. Low melting point
4. Don’t conduct electricity when in solution
EX: H2O Cl2

31. COVALENT VS. IONIC BONDS
Covalent bonds
Ionic bonds
Share valence electrons
Transfer valence electrons
Occur between nonmetals only
Occur between metals and nonmetals
No ions involved
Forms + and – ions
Low Melting Point
High Melting Point
Ex. H2 CCl4
Ex. NaCl K2S 31

32. Lewis Dot Diagrams for Covalent Bonds• F H • H F • F H • H F
by sharing
electrons with
other atoms.
Each atom
attempts to attain
a filled outer shell • H F • F H
(typically a noble gas electron configuration)

33. Structural Formulas Bonds are represented with a dashed line F H F H
Circle all bonded electron pairs • F H
Lewis dot Diagram
Bonds are represented with a dashed line
1 single covalent bond (1 shared pair of e-s)
3 unshared pairs of e-s • F H
Structural Diagram

34. Covalent Bonds:
Dogs of equal strength.
Covalent bonds can be thought of as two or more dogs with equal attraction to the bones.  Since the dogs (atoms) are identical (same electronegativities), then the dogs share the pairs of available bones evenly. 

36. Naming Covalent Compounds
Ex: CO CO2
1. The first element’s name doesn’t change.
carbon carbon
2. Second element ends in IDE
carbon oxide carbon oxide
3. Use prefixes to distinguish between compounds & to show how many atoms of each element are present
carbon monoxide carbon dioxide

37. Prefixes for Molecular Compounds:1
mono
Don’t use for first named element 2 di
Ex: CO 3
tri
carbon monoxide 4
tetra 5
penta 6
hexa 7
hepta 8
octa 9
nona 10
deca
1. drop vowel on prefix if element starts with vowel
EX: monooxide =
monoxide
2. Don’t drop vowel for
di and tri prefixes

39. phosphorus pentachloride
EXAMPLES: NO
NO2
N2O
N2O3
PCl5
CS2
SF6
nitrogen monoxide
nitrogen dioxide
dinitrogen monoxide
dinitrogen trioxide
phosphorus pentachloride
carbon disulfide
sulfur hexafluoride

40. How to Write a Molecular Formula:
Write down element symbol
Prefixes give you what subscripts to use
Ex:
Carbon tetrachloride
Sulfur trioxide
Tetraiodine nonoxide
Ex:
Carbon tetrachloride
Sulfur trioxide
Tetraiodine nonoxide
Ex:
Carbon tetrachloride
Sulfur trioxide
Tetraiodine nonoxide
Ex:
Carbon tetrachloride
Sulfur trioxide
Tetraiodine nonoxide
CCl
CCl4 SO
SO3
I O
I4O9

41. Warm-up
Name the following:
P2O5
C3H8
K2O
Cl2O7
Al2O3

42. How to review for a quiz or test
1. create study checklists
2. create summary notes
Organize your notes (graphic organizers)
Create Flashcards
Form study groups
Create possible test questions.

43. ???? Bond Energies