1. I. Why Atoms Combine Chemical Formula Chemical Bond Stability

2. What is a compound? What does the word compound mean in this sentence?
“I have a compound fracture in my leg.”

3. What is a compound? Compounds involve more than one element/atom.
Table salt is a compound made of two elements, sodium (Na) and chlorine (Cl).

4. What is a compound? A compound always has the same chemical formula.
Remember that a chemical formula helped you to categorize a substance as a mixture or a compound a few chapters ago.

5. H2O A. Chemical Formula Shows: 1) elements in the compound
2) ratio of their atoms
H2O
1 oxygen atom
2 hydrogen atoms

6. Practice Silver chloride = one atom of silver + one atom of chlorine
_______________________
Hydrochloric acid = one atom of hydrogen + one atom of chlorine
________________________

7. Potassium chloride = one potassium atom + one chlorine atom
ammonium bromide = one atom of nitrogen + four atoms of hydrogen + one atom of bromine

8. Practice
Hydrogen peroxide= two atoms of hydrogen + two atoms of oxygen
______________________
Magnesium carbonate = one atom of magnesium + one atom of carbon + three atoms of oxygen
__________________________

9. Practice
Glucose = six atoms of carbon + twelve atoms of hydrogen + six atoms of oxygen
_______________________
sucrose, C12H22O11
Show me the elements and atom amount

10. B. Chemical Bond
Strong attractive force between atoms or ions in a molecule or compound.
The higher the melting and boiling points of a substance, the stronger the attractive forces.

11. C. What is an ion?
An ion is an atom with a net charge because it no longer has the same number of electrons and protons.
An ion is formed when atoms need to give up or take electrons to fill their outer energy level.

12. Ions
Going back to sodium (Na) and chlorine (Cl) forming table salt, sodium gave up an electron to chlorine.
So sodium chloride is made of sodium and chlorine ions. Both elements now have a charge.

13. Chemical bonds Formed by either: transferring e- (losing or gaining)
sharing e-

14. Ne D. Stability Octet Rule
most atoms form bonds in order to have 8 valence e-
full outer energy level
like the Noble Gases! Ne
Stability is the driving force behind bond formation!

15. C. Stability
Transferring e-
Sharing e-

16. II. Kinds of Chemical Bonds Ionic Bond Covalent Bond Comparison Chart

17. A. Ionic Bond Attraction between 2 oppositely charged ions
Ions - charged atoms
formed by transferring e- from a metal to a nonmetal

18. A. Ionic Bond
ions form a 3-D crystal lattice
NaCl

19. A. Oxidation Number The charge on an ion.
Indicates the # of e- gained/lost to become stable. 1+ 2+ 3+ 4+ 3- 2- 1-

20. Metallic Bonds Metals: can conduct electricity flexible
can be hammered into thin sheets
stretched into thin wire

21. Metallic Bonds Electrons move freely between metal atoms
Metal atoms pack closely together so their outer orbitals (energy levels) overlap
So electrons are free to move from atom to atom

22. Metallic Bonds
Valence electrons of metals are not associated with a particular metal ion.
This helps electricity to move fast along metal wires.

23. B. Covalent Bond Attraction between neutral atoms
formed by sharing e- between two nonmetals

24. B. Covalent Bond
covalent bonds result in discrete molecules
NH3
H2O
Cl2

25. Covalent Bond –sharing

26. B. Covalent Bond Nonpolar Covalent Bond e- are shared equally
usually identical atoms

27. + - B. Covalent Bond Polar Covalent Bond
e- are shared unequally between 2 different atoms
results in partial opposite charges + -

28. B. Covalent Bond
Nonpolar
Polar
Ionic
View Bonding Animations.

29. C. Comparison Chart IONIC COVALENT transferred from metal to nonmetal
shared between nonmetals
Electrons
Melting
Point
high
low
Soluble in
Water
yes
usually not
yes (solution or liquid)
Conduct Electricity no
crystal lattice of ions, crystalline solids
molecules, odorous liquids & gases
Other
Properties

31. III. Naming Molecular Compounds Molecular Names Molecular Formulas
Chemical Bonds
III. Naming Molecular Compounds
Molecular Names
Molecular Formulas

32. A. Molecular Names Write the names of both elements.
Change the final ending to -ide.
Add prefixes to indicate subscripts.
Only use mono- prefix with oxide.

33. A. Molecular Names PREFIX mono- di- tri- tetra- penta- SUBSCRIPT 1 2 34 5

34. A. Molecular Names PREFIX hexa- hepta- octa- nona- deca- SUBSCRIPT 6 78 9 10

35. A. Molecular Names CCl4 N2O carbon tetrachloride SF6
dinitrogen monoxide
sulfur hexafluoride

36. B. Molecular Formulas Write the more metallic element first.
Add subscripts according to prefixes.

37. B. Molecular Formulas phosphorus trichloride dinitrogen pentoxide PCl3
dihydrogen monoxide
PCl3
N2O5
H2O

38. B. Molecular Formulas The Seven Diatomic Elements
Br2 I2 N2 Cl2 H2 O2 F2

39. IV. Naming Ionic Compounds Oxidation Number Ionic Names Ionic Formulas
Chemical Bonds
IV. Naming Ionic Compounds
Oxidation Number
Ionic Names
Ionic Formulas

40. A. Oxidation Number The charge on an ion.
Indicates the # of e- gained/lost to become stable. 1+ 2+ 3+ 4+ 3- 2- 1-

41. B. Ionic Names Write the names of both elements, cation first. (metal)
Change the anion’s ending to -ide. (nonmetal)
For ions with variable oxidation #’s, write the ox. # in parentheses using Roman numerals. Overall charge = 0. (Transition metals)

42. B. Ionic Names
NaBr
Be3P2
sodium bromide
Beryllium phosphide

43. C. Ionic Formulas Write each ion. Put the cation first.
Overall charge must equal zero.
If charges cancel, just write the symbols.
If not, crisscross the charges to find subscripts.

44. C. Ionic Formulas
potassium chloride
K+ Cl-  KCl

45. C. Ionic Formulas Na+ + O2- ---> Na2O calcium oxide Ca2+ O2-  CaO
Sodium oxide
Na+ + O > Na2O

46. Ionic Formulas
Aluminum chloride
Al Cl- ---> AlCl3

47. Covalent Bond Naming SiO2 silicon dioxide NO nitrogen monoxide XeF4
Xenon tetrafluoride

48. Covalent Bond Naming Tetraphosphorus trisulfide P4S3 PBr3
phosphorus tribromide
CS2
carbon disulfide

49. Covalent bond formula Nitrogen trifluoride NF3 Dinitrogen pentoxide
N2O5

50. Covalent Bond formula
Trisilicon tetranitride
Si3N4
Carbon dioxide
CO2