1. Naming Compounds and Writing Formulas

2. Key Question:
Why Do Atoms Combine In Certain Ratios?

3. Review of Oxidation Numbers

4. Chemical Compound Quiz
Sodium chloride is a flavorful addition to many foods. What is the common name?
Salt

5. Review of Oxidation Numbers
All compounds have an electrical charge of zero (they are neutral).
An oxidation number indicates the charge on the atom (or ion) when electrons are lost, gained, or shared in chemical bonds. 5

6. Oxidation Numbers
A sodium atom always ionizes to become Na+ (a charge of +1) when it combines with other atoms to make a compound.
Therefore, we say that sodium has an oxidation number of 1+.
What is chlorine’s oxidation number? 6

7. 7

8. H He Li Be B C N O F Ne Na Mg Al Si P S Cl Ar 1 2 3 4 5 6 7 8
Valence Electrons
The Number Of Electrons In The Outside Energy Level. 8

9. Ionic Bonds
On the periodic table, strong electron donors are on the left side (alkali metals).
Strong electron acceptors are on the right side (halogens).
The further apart two elements are on the periodic table, the more likely they are to form an ionic compound. 9

10. As heat energy is added to ice, the temperature increases until it reaches 0°C.
Then the temperature stops increasing.
As you add more heat, more ice becomes liquid water but the temperature stays the same.
This is because the added energy is being used to break the intermolecular forces and change solid into liquid.
Once all the ice has become liquid, the temperature starts to rise again if more energy is added. 10

11. Covalent Bonds
Covalent compounds form when elements have roughly equal tendencies to accept electrons.
Elements that are both nonmetals and therefore close together on the periodic table tend to form covalent compounds. 11

12. Oxidation Numbers, Lewis Structures And Chemical Formulas
Remember, the oxidation numbers for all the atoms in a compound must add up to zero. 12

13. Multiple Oxidation Numbers
Some periodic tables list multiple oxidation numbers for most elements.
This is because more complex bonding is possible.

14. Naming Compounds and Writing Formulas

15. Types Of Chemical Compounds
Ionic metal ion – nonmetal ion
Covalent two nonmetals
Polyatomic Compound ~ Has at least one polyatomic ion

16. Naming Compounds with Ionic Bonds

17. Tips To Keep In Mind When Naming And Writing Formulas:
Always keep your Periodic Table handy – You should have it in front of you ALWAYS when you are naming and writing formulas.
Remember that metals (except Hydrogen) are found to the left of the stairstep on the Periodic Table.
Nonmetals are found on the right side of the stairstep of the Periodic Table.
Metalloids are the 6 elements on or below the stairstep except Al, Po and At. For naming purposes they will tend to behave like nonmetals.

19. Naming Binary Compounds
A ionic compound is held together by ionic bonds.
Covalent compounds consist of covalently bonded atoms.
Each type of compound has its own naming rules.

20. How Do You Name Binary Ionic Compounds?
(Composed Of Two Elements – A Metal And A Nonmetal)
Name the first ion
Name the second ion changing the suffix to –ide.

21. Naming Binary Ionic Compounds
MgBr2 is magnesium (name of first element) + brom (root name of second element) + ide suffix = magnesium bromide

22. Examples Name the metal ion
NaCl
Sodium
Chloride
Name the metal ion
CaO
Name the nonmetal ion, changing the suffix to –ide.
Calcium
Oxide
Al2S3
Aluminum
Sulfide
MgI2
Magnesium
Iodide

23. Non - Examples You should recognize a problem with this one… BaNa2
This is two metals – not an ionic compound

24. Exit Quiz LiCl Lithium Chloride Name the metal ion CaSe
Name the nonmetal ion, changing the suffix to –ide.
Calcium
Selenide
Ga2S3
Gallium
Sulfide
MgF2
Magnesium
Fluoride

25. What About The Transition Metals And Using Roman Numerals
What About The Transition Metals And Using Roman Numerals? How Does That Work?
Let’s See.
Notice – metal and nonmetal.
FeO
Name the first ion. Since the first ion is a transition element, you must use a Roman Numeral to represent the charge.
Iron
(II)
Oxide
How do you know the charge?
Deductive reasoning.
All compounds are neutral.
Oxygen has a -2 charge (group 16)
Therefore, iron must have a +2 charge since there is one iron and one oxygen. Iron gets a Roman Numeral (II).
Isn’t this easy and FUN!!!

26. Name the first ion. Since it is a transition metal, you must use a Roman Numeral.
Which Roman Numeral? The Roman Numeral is the same as the charge of the ion.
How do you find the charge?
Deductive reasoning!
All compounds are neutral
Sulfur has a -2 charge (group 16)
There are two coppers
Therefore each copper must have a +1 charge for the compound to be neutral
Cu2S
Copper
(I)
Sulfide

27. MnO2 Manganese (IV) oxide
Name the first ion. Since it is a transition metal, you must use a Roman Numeral.
How do you determine the Roman Numeral?
It is the same as the charge.
What is the charge of Mn?
Oxygen (group 16) has a -2 charge and a total of -4 charge.
There are two oxygens with one manganese.
Therefore Mn must have a +4 charge for this compound to be neutral.
Manganese
(IV)
oxide

28. You need to remember the charges for these.
And Remember, There Are Three Transition Elements Which Do Not Require A Roman Numeral Because They Have Single Definite Charges. These Are:
Zinc – Zn2+ Cadmium – Cd2+ Silver – Ag+
You need to remember the charges for these.
Ag2O
Name the first ion.
Name the second ion changing the suffix to –ide.
Silver
oxide
No Roman Numerals needed for these.
ZnCl2
Name the first ion.
Name the second ion changing the suffix to –ide.
Zinc
chloride

29. How Do You Write Formulas For Ionic Compounds Given The Name?
Two Simple Steps:
Write the symbol and charge of each ion
Balance the charges by providing subscripts
Magnesium
chloride
Write the symbol and charge of each ion
Mg Cl-
Balance the charges by supplying subscripts. Subscripts tell how many of each atom is present.
Cl-
MgCl2
You need a second Cl-1 to balance the charges

30. Iron (III) bromide Fe3+ Br - Br - Br - FeBr3
Write the symbol and charge of each ion. The charge of the iron is provided by the Roman Numeral.
Br -
Br -
FeBr3
Balance the charges by supplying subscripts. The subscripts tell how many of each ion is needed to balance the compound.
You’ll need three bromine ions to balance the one iron.

31. Aluminum Sulfide Al3+ S2- Al3+ S2- S2- Al2S3
Write the symbol and charge of each ion.
Al S2-
Balance the charges by supplying subscripts.
Al3+
S2-
In this case the charges do not evenly divide into each other. You must find the least common multiple. SIX
S2-
Al2S3
How many aluminums are needed to arrive at a +6 charge? 2
How many sulfurs are needed to arrive at a -6 charge? 3

32. Writing Formulas a Little Quicker
Iron and oxygen combine to form a compound. Iron (Fe) has an oxidation number of 3+. Oxygen (O) has an oxidation number of 2–.
Predict the chemical formula of this compound.

33. Simply cross the oxidation numbers and make them positive
Writing Formulas a Little Quicker 3+ 2- Fe O 2 3
Simply cross the oxidation numbers and make them positive

34. Let’s Try Another One:
Manganese (IV) phosphide 4+ 3- Mn P 3 4

35. Cross but in this case they must be dropped!
Let’s Try One More:
Manganese (IV) oxide
Cross but in this case they must be dropped! 4+ 2- Mn O 2 4
MnO2

36. Exit Quiz – Formula for magnesium chloride?2+ 1-
MgCl2

37. Exit Quiz – Formula for sodium oxide?1+ 2-
Na2O

38. Exit Quiz – Name for: 6+ 6- 3+ 2-
Fe2O3
Iron (III) oxide

39. Exit Quiz: Formula for Chromium (IV) oxide4+ 2-
Cr O 2 4
CrO2

40. Naming Compounds and Writing Formulas II

41. The Second Category of Compounds –
Covalent Compounds
These compounds contain two elements
The term “covalent” indicates that these elements are joined by a covalent bond.
They must therefore be nonmetals.
Bottom line – 2 elements – both nonmetals
To name and write formulas for these, you must know some numerical prefixes.

42. Naming – You Must Use Prefixes.
1 = mono 3 = tri = penta = hepta = nona
2 = di 4 = tetra 6 = hexa = octa = deca
Steps
The first nonmetal only gets a numeric prefix when there is more than one. No prefix if there is only one.
The second element always gets a numeric prefix and always has a suffix of -ide

43. Naming Binary Molecular Compounds
As with binary ionic compounds, the ending of the name of the second element in the compound is modified by adding the suffix –ide.

44. CO2
Carbon dioxide CO
Carbon monoxide
N2O4
Dinitrogen tetroxide
H2O
Dihydrogen monoxide
CCl4
Carbon tetrachloride
Name the first element. Since there is only one, no prefix is needed.
The second element always gets a prefix and a suffix of –ide.
Name the first element. Since there are two present, the prefix “di” is needed. The second element always gets a prefix and a suffix of –ide.

45. What do you think about this one???
Be careful. This is a metal and nonmetal.
Always keep your Periodic Table in front of you for reference.
You may have been tempted to say “aluminum trichloride”. This is INCORRECT!
This is an IONIC compound. No prefixes are used. Simply name it aluminum chloride.
AlCl3

46. Given The Names Of Molecular Compounds, How Do You Write The Formulas?
Very easily done!!! The prefixes tell you how to write the formulas. DO NOT CONSIDER CHARGES. NONMETALS ARE ALL NEGATIVE SO TO USE CHARGES DOES NOT WORK!

47. Diphosphorous pentachloride
Silicon dioxide
Silicon and oxygen are both nonmetals.
The lack of a prefix on silicon means that there is only ONE silicon.
The prefix “di” in front of oxide means that there are TWO oxygens.
SiO2
Diphosphorous pentachloride
Phosphorous and chloride are both nonmetals.
The prefix “di” means that there are TWO phosphorouses (Is that a word?)
The prefix “penta” before chlorine means that there are five chlorines.
P2Cl5

48. Nitrogen monoxide NO Nitrogen and oxygen are both nonmetals.
The lack of a prefix on nitrogen means only ONE nitrogen.
The prefix “mono” on oxygen indicates ONE oxygen. NO
Is this not sooooooo easy!??

49. Type 3: Compounds That Contain At Least One Polyatomic Ion.
What is a polyatomic ion?
Let’s look at the name to try to understand.
It is an ion – that means it has a charge.
It is polyatomic – that means it is made of more than one atom.
Let’s look at some examples of polyatomic ions.

50. CO32- carbonate You need to learn these!!!
This ion is composed of one carbon and three oxygens and the entire group has a charge of -2.
Polyatomic ion – Group of atoms that act as a unit and carry a charge.
You have been given a list of other polyatomic ions
You need to learn these!!!

51. How Do You Recognize Ionic Compounds?
Composed of two ions in which at least one is a polyatomic ion.
There is only one positive polyatomic ion (NH4+1)
Three possible types of These Ionic Compounds:
Ammonium + negative ion (nonmetal)
Metal (positive ion) + negative polyatomic ion
Ammonium + negative polyatomic ion
Polyatomic Ion

52. Naming Compounds with Polyatomic Ions as Cations
NH4Cl is ammonium (the name of the ion from chart) + chlor (root name of the second element) + ide suffix = ammonium chloride.

53. Naming Compounds with Polyatomic Ions as Anions
Name the first ion.
Name the second ion. Isn’t that simple??!!
Examples:
When you look at this compound you should recognize that this is NOT binary (made up of 2 elements). There are THREE elements present. When you see this, immediately look for a polyatomic ion. Carbonate is present here.
Na2CO3
Sodium
carbonate
Notice that you do NOT change the suffix – just name the polyatomic ion
Name the first ion.
Name the second ion.

54. All compounds are neutral. You know the charge of OH (-1)
Fe(OH)3
Name the first ion.
Iron
(III)
Remember that iron requires a Roman Numeral since it is a transition element. What Roman Numeral should be used?
hydroxide
Since there are 3 OH groups, each with a -1 charge, the charge of the iron must be +3 for the compound to be neutral
The Roman Numeral comes from the charge of the ion. How do you find the charge of the iron?
You know two things:
All compounds are neutral.
You know the charge of OH (-1)
Name the polyatomic ion.

55. NH4Cl Ammonium chloride Name the first ion. Name the second ion.
Notice that since the second ion is a nonmetal that, like binary ionic compounds, the suffix of the nonmetal changes to –ide.

56. Naming Compounds with Polyatomic Ions as Cations and Anions
Name the first ion.
(NH4)3PO4
Ammonium
Name the second ion.
phosphate

57. Cu2SO4
Name the first ion.
You should realize that you need a Roman Numeral since copper is a transition metal.
Copper
(I)
sulfate
Name the second ion.
The Roman Numeral is the same as the charge.
What is the charge?
The charge of sulfate is -2.
Since there are two coppers, the charge of the copper must be +1.

58. How Do You Write Formulas For Polyatomic Ionic Compounds?
Very Much Like Writing Formulas For Binary Ionic Compounds.
Three Steps:
Write the formulas/symbols of each ion.
Balance the charges by supplying subscripts.
If a subscript is needed for a polyatomic ion, it must be put in parentheses with the subscript on the outside.
Let’s do some!!

59. Aluminum nitrate
First, you can tell from the name that there is a polyatomic ion present (nitrate). All binary ionic compounds have suffixes of –ide.
Al NO3-
Al(NO3)3
Write the formula/symbol and charge of each ion.
Balance the charges by supplying subscripts.
Since Al is +3 and NO3 is -1, you need a total of 3NO3- to balance one Al3+
Since you will need a subscript of 3 for NO3-, you need to put this in parentheses with the 3 outside.

60. Lead (IV) acetate Pb4+ C2H3O2- Pb(C2H3O2)4 Calcium phosphate
Write the formula/symbol and charge of each ion.
Pb C2H3O2-
Balance the charges by supplying subscripts. Since Pb is +4 and C2H3O2 is -1, you will need 4 C2H3O2-1 to balance 1Pb+4
Pb(C2H3O2)4
Write the formula/symbol and charge of each ion.
Calcium phosphate
Ca PO43-
Balance the charges by supplying subscripts. Since Ca is +2 and PO4 is -3, you will need 3 Ca+2 to balance 2 PO4-3
Ca3(PO4)2

61. Exit Quiz CO2 SO N2O5 CF4 SO3 CO B2O3 NF5 Carbon dioxide
Sulfur monoxide
N2O5
Dinitrogen pentoxide
CF4
Carbon tetrafluoride
SO3
Sulfur trioxide CO
Carbon monoxide
B2O3
Diboron trioxide
NF5
Nitrogen pentafluoride

62. Exit Quiz Al3+ combines with sulfate (SO4)2– to make aluminum sulfate.
Write the chemical formula for aluminum sulfate.

63. Exit Quiz Answer 3+ 2- Al
(SO4) 2 3

64. Let’s Try Another One:
Manganese (IV) phosphate 3- 4+
(PO4) Mn 3 4

65. (CO3) Mn Mn(CO3)2 4+ 2- 2 4 Let’s Try One More:
Manganese (IV) carbonate 4+ 2- Mn
(CO3) 2 4
Mn(CO3)2