1. By gaining or losing electrons, atoms become ions.
Ion: A Charged Atom
By gaining or losing electrons, atoms become ions.
ANIONS: Atoms that have gained electrons and have a negative charge -Nonmetals form anions
CA+IONS: Atoms that have lost electrons and have a positive charge -Metals form cations

2. OXIDATION NUMBERS ARE PERIODIC
Group # 1 2 13 14 15 16 17 18
Oxid. #

3. Monatomic Ions: 1 Atom Ions To Name:
Positive Monatomic Ions: Name the metal, if it is a transition metal, add a Roman Numeral to indicate the number of the charge
Negative Monatomic Ions: Change the ending of the elements name to –ide
Example--Name the following:
Cu+1 Ca+2 Cl-

4. Polyatomic Ions: More than 1 atom ions
Polyatomic Ions end in –ate or –ite and are found in the chart at the bottom of your periodic table…just look them up
Examples: Name the following
CO32- OH-
Write the formulas of the following:
Nitrite Perchlorate

5. + (Metals form positive ions)
ATTRACT
What do opposites do?
A metal will lose electrons to become stable. What charge
will that metal have after it loses electrons?
A nonmetal will gain electrons to become stable. What
charge will that nonmetal metal have after it gains electrons?
If metal ions are in a container with nonmetal ions…What will happen?
+ (Metals form positive ions)
- (Nonmetals form negative ions)
ATTRACT—Come together in an ionic bond

7. Ionic Bond
The strong attractive force between ions of opposite charge. Occurs when one atom transfers electrons to another atom to become stable
Electrons are transferred in an ionic bond.
Ionic bonds form between metals and nonmetals

8. EMPIRICAL FORMULA Chemical formula for an ionic compound
Lowest whole number ratio of ions in an ionic compound

9. EMPIRICAL FORMULA
Al2O3
Subscript: # written to the lower right of a chemical symbol that shows the number of atoms of that element present in the compound

10. Using oxidation numbers to determine the empirical formula of a compound.1
Because compounds are all _____________ in charge, the total sum of the oxidation numbers in a compound must be ________.
Determine the number of each ion necessary so that the sum of the charges is 0.

11. Using the crisscross method to determine the empirical formula of an ionic compound.2
Write the symbol of charge of each ion in the compound
Crisscross each ions numerical charge down to the subscript of the other ion
Can check your answer—the charges will still add up to be 0
Sr N3-
Sr3N2

12. Naming Ionic Compounds
Make sure it is an ionic compound. How can you tell?
Determine if it’s a binary or a ternary ionic compound.
Binary =
Ternary =
Ternary compounds contain a ____________________
Ionic compounds will have only _________words in their names. This is because all ionic compounds are composed of just 1 ____________ and just 1 ______________.
If the compound has more than 2 elements than one of the ions is a ______________________________ ion.
It contains a metal & nonmetal(s) or ammonium & nonmetal(s).
2 elements
More than 2 elements
Polyatomic ion 2
cation
anion
Polyatomic ion

13. Naming a Binary Ionic Compound
To Name an Ionic Compound
CaCl2
Fe2O3
Na2O
Name the metal
If the metal is a transition metal, add a Roman numeral in parentheses to indicate it’s charge
Name the nonmetal, changing its suffix to –ide

14. To Name an Ionic Compound
EXAMPLES
To Name an Ionic Compound
CuCl
MnO
AlBr3
Name the metal
If the metal is a transition metal, add a Roman numeral in parentheses to indicate it’s charge
Name the nonmetal, changing its suffix to -ide

15. Naming a Ternary Ionic Compound
To Name an Ternary Ionic Compound
CaSO4
Cu(C2H3O2)2
NH4OH
Does the formula begin with NH4? If so the first word is ammonium. If not, name the metal
If the metal is a transition metal, add a Roman numeral in parentheses to indicate it’s charge
Name the polyatomic ion.

16. Naming a Ternary Ionic Compound
To Name an Ternary Ionic Compound
Al(ClO)3
KSCN
NaHCO3
Does the formula begin with NH4? If so the first word is ammonium. If not, name the metal
If the metal is a transition metal, add a Roman numeral in parentheses to indicate it’s charge
Name the polyatomic ion.

17. Examples Name the following ionic compounds. LiCl Ca(OH)2 (NH4)2S
KI CoO Ni(NO3)2

18. IONIC VS. COVALENT BONDING
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19. Molecular Compounds
Molecular compounds form when elements __________________ electrons to form compounds.
Also known as covalent compounds.
How can you distinguish a molecular compound from an ionic compound based on its chemical formula or chemical name?
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Ionic Compounds are made of metals combined with nonmetals. Molecular compounds are made of all nonmetals!

20. Which type of bond would form between the following elements?
MgCl2 CI4 AlN
CO2 OF2 SnO2

21. Molecule A group of atoms united by covalent bonds
Polyatomic Ions are molecules that have charge!

22. DIATOMIC MOLECULES:
Some elements only exist in nature as molecules consisting of 2 atoms of that element.
Why? More stable as a pair!
The 7 diatomic elements are: HONClBrIF

23. Molecular Substance Molecular Formula Substance made of molecules
Tells how many atoms of an element are in a single molecule of a compound
The chemical formula of a covalent compound is not the lowest whole number ratio
Different from an EMPIRICAL FORMULA which gives the lowest whole number ratio of ions in an IONIC COMPOUND

24. To Name a Molecular Compound
Name the 1st element. If there is more than one of that element, use the appropriate prefix (mono- is not used on the first element)
Name the last element using the appropriate prefix and changing its ending to –ide.
Since there are no metals in molecular compounds, no Roman numerals are used.

25. NUMERICAL PREFIXES 1 Mono- 2 Di- 3 Tri- 4 Tetra- 5 Penta- 6 Hexa- 7
Hepta- 8
Octa- 9
Nona- 10
Deca-

26. Examples N2O4 PCl5 NO2 Dinitrogen tetroxide Phosphorous pentachloride
Nitrogen dioxide

27. Chemical Formulas for Molecular Compounds
Use the prefixes to determine the chemical formula
Since molecular compounds do not involve the transfer of electrons, there are no ions—do not get charges and no crisscrossing!

28. Examples Nitrogen trifluoride Diphosphorus pentoxide
Carbon tetrachloride
NF3
P2O5
CCl4

29. HYDRATES
An ionic compound that contains water within its crystal structure
Anhydrous: A compound in which all water has been removed.
The water may be evaporated off of a hydrate to leave the anhydrous form of the substance

30. HYDRATES To Identify a hydrate BaCl2  3H2O barium chloride trihydrate
To Name a hydrate
Name the ionic compound followed by the word hydrate with a prefix to indicate the # of water molecules attached.
MgSO4  2H2O
To Write the Formula for a Hydrate
Use the crisscross method to determine the formula of the ionic compound, followed by a dot, followed by the # of water molecules indicated by the prefix.
Copper(II) chloride pentahydrate

31. Acids A molecular substance that dissolves in water to produce H+ ions
The chemical formula starts with H (we will assume all are dissolved in water)

32. To Name an Acid containing a Polyatomic Ion
To Name a Binary Acid
“Hydro”-root name of anion-“ic Acid”
Ex: Hydrobromic Acid
To Name an Acid containing a Polyatomic Ion
Root name of Polyatomic Ion- “ic” Acid
Ex: Sulfuric Acid

33. To determine the formula of an acid
Consider Hydrogen an Ion: H+
Determine the charge of the anion
Crisscross charges
H+ S2-  H2S