1. Unit 2 – Nomenclature and Formulas
Formulas – denotes type and ratio of atoms in a compound
Nomenclature – system of naming chemical compounds

2. Why do CHEMISTS use a system of naming
Why do CHEMISTS use a system of naming? Why not just give each chemical a name like “SAM”, “jillium” or “jorge”?
(Hint: How many known compounds have been identified as of 2015?)
ANS: 100 MILLION! How easy would be to remember 100 million separate random names?
Is there any pattern in human names? What is a common pattern to show that a group of people are members of the same family?
ANS: In western civilization, family members often share the same last name.

3. Examples NaCl – sodium chloride FeCl3 – iron(III) chloride
CO2- carbon dioxide

4. Aluminum chloride, AlCl3 Iron(III) chloride, FeCl3
THERE ARE 3 SETS OF RULES USED TO NAME DIFFERENT TYPES OF COMPOUNDS. SEE IF YOU CAN ARRANGE THE FOLLOWING COMPOUND NAMES INTO 3 DIFFERENT GROUPS.
Aluminum chloride, AlCl3
Iron(III) chloride, FeCl3
Nickel(II) bromide, NiBr2
Dinitrogen tetroxide, N2O4
Magnesium oxide, MgO
Sodium fluoride, NaF
Carbon dioxide, CO2
Sulfur trioxide, SO3
Copper (II) chloride, CuCl2

5. Aluminum chloride, AlCl3 Iron(III) chloride, FeCl3
THERE ARE 3 SETS OF RULES USED TO NAME DIFFERENT TYPES OF COMPOUNDS. SEE IF YOU CAN ARRANGE THE FOLLOWING COMPOUND NAMES INTO 3 DIFFERENT GROUPS.
Aluminum chloride, AlCl3
Iron(III) chloride, FeCl3
Nickel(II) bromide, NiBr2
Dinitrogen tetroxide, N2O4
Magnesium oxide, MgO
Sodium fluoride, NaF
Carbon dioxide, CO2
Sulfur trioxide, SO3
Copper (II) chloride, CuCl2

6. 3 Types of Compound Names
Class 1:
Aluminum chloride, AlCl3
Magnesium oxide, MgO
Sodium fluoride, NaF
Class 2:
Iron(III) chloride, FeCl3
Nickel(II) bromide, NiBr2
Copper (II) chloride, CuCl2
Class 3:
Dinitrogen tetroxide, N2O4
Carbon dioxide, CO2
Sulfur trioxide, SO3

7. Foundations for Understanding Nomenclature and Formulas
Understanding Nomenclature and Formulas Requires a Basic Understanding of Chemical Bonding
Understanding Chemical Bonding Requires some basic knowledge of the of the Structure of Atoms and the Periodic Table!

8. The Periodic Table of the Elements
Elements are arranged in order according to the number of PROTONS (atomic #).
Periodic Table is organized into 7 rows or PERIODS
and 18 vertical columns called GROUPS or FAMILIES

9. MOST IMPORTANT PRINCIPLE OF ORGANIZING ELEMENTS ON PERIODIC TABLE:
Elements in the same family (group or vertical column) will always have similar chemical and physical properties.

10. Example: Group 8A (Family 18) NOBLE GASEs
All elements of this family are chemically unreactive gases.

11. 7 diatomic elements – memorize for testH2 N2 O2 F2
Cl2
Br2 I2
“HOFBrINCl”

12. Metals and Nonmetals
METALS - Shiny, easily shaped, excellent conductors of heat and electricity
NONMETAL -Lack metallic properties

13. Staircase dividing Metals and Nonmetals
RIGHT
LEFT

14. METALS Metals: found to the LEFT of the staircase.
In reactions with nonmetals tend to lose electrons to form + ions.

15. NONMETALS Found to the RIGHT of the staircase.
In reactions with metals, nonmetals GAIN electrons to form negative ions.

16. Homework 2-1, p. 108 Zumdahl
1) What property determines the numerical order of elements on the periodic table?
2) In which direction on the periodic table, horizontal or vertical, are elements with similar chemical properties aligned? What are families of elements with similar chemical properties called?
3) List the characteristic physical properties distinguish metallic elements from the nonmetallic elements.
4) Where are the metallic elements found on the periodic table? Are there more metallic elements or nonmetallic elements?

17. Electrons are arranged inside the atoms in ENERGY LEVELS

18. First energy level can hold up to 2 electrons.
When one level is filled, electrons are placed in the next level out from the nucleus.
Level 1
Level 2

19. First energy level can hold up to 2 electrons.
Energy levels 2 thru 7 (ignoring transition metals) hold up to 8 valance electrons.
Level 1
Level 2

20. The outermost electrons are called VALENCE ELECTRONS.

21. How many valence e- are present for each element?1 2 7 4 1 8 1 4 7 8

22. Lewis Dot Structures use dots to represent valance electronsH He C Li

23. Draw the Lewis Dot structures for the following atomsNa

24. Work hw 2-1, workbook problems #5,6
1) What is the difference between core or inner electrons and valence electrons? Which type of electron, core or valence, is most important in determining chemical behavior?
2) The electron energy levels of Na, Cl and Ne are given below: Draw a Lewis Dot structure for each element.

25. Work hw 2-1, workbook problems #5,6
1) What is the difference between core or inner electrons and valence electrons? Valence = outermost electron; Which type of electron, core or valence, is most important in determining chemical behavior?
2) The electron energy levels of Na, Cl and Ne are given below: Draw a Lewis Dot structure for each element.

26. What is the relationship between Group # and # of valence electrons?

27. Group # and valence electrons
The GROUP # at the top of groups 1A,2A,3A,4A,5A,6A,7A and 8A indicates the number of VALENCE (outermost) electrons.
HW 2-2, #1 and #2

28. HW 2-2, #2: # Valence e- = Group #

29. Valence Electrons and Chemical REACTIONS
The # of valence electrons determines CHEMICAL BEHAVIOR
Atoms with a filled valence level will NOT react chemically
A completely filled valence level = chemically STABLE or INERT
Atoms WITHOUT a filled valence level WILL CHEMICALLY REACT in order to obtain a COMPLETELY FILLED valence electron level.

30. Reactive vs inert: why are MODERN blimps filled with He GAS instead of H GAS?
Video

31. Inert: Helium
Helium has a completely filled first energy level (2 valence electrons)
Helium will NOT burn when mixed with oxygen and a spark. Filled valence level = UNREACTIVE

32. Reactive vs. Inert
Hydrogen – has only 1 valence e-; needs 1 e- to fill outer level
Hydrogen needs to gain 1 valence electron order to fill its outer energy level.
Hydrogen is extremely reactive. It explodes when mixed with oxygen and a spark.

33. H reacts with O to obtain a filled outer level like He

34. Inert vs. Reactive: Lithium
Li- filled inner level but 1 valence electron in second level = REACTIVE
Helium filled valence level is INERT
Link to Lithium combustion video

35. Lithium and Oxygen react to form Lithium oxide
Note that no dots are shown for Li+1 because valence e- (level 2) has been lost

36. REACTIVE vs INERT Unfilled Valence Level = REACTIVE
Filled Valence Level = INERT

37. Valence e- and Chemical Rxns
Atoms without filled valence levels LOSE,GAIN or SHARE valence electrons to reach stability, a full valence level.

38. p: p: + + +
e-: e-:

39. What patterns do you notice?

40. Elements in the same column have the same charge

41. Predicting charges in compounds containing metals bonded to nonmetals
Metals want to lose all valance e-
Examples:
M [M] e-
M [M] e-
M [M] e-
Nonmetals want to add e- to total 8 valence e-
X e X
X e X
X e X

42. WORK HW 2-2, #3
3A) Draw the Lewis dot structure for each element Ar and K.
B) Predict which element Ar or K would unreactive (inert). Explain your reasoning.

43. WORK HW 2-2, #3
3A) Draw the Lewis dot structure for each element Ar and K.
B) Predict which element Ar or K would unreactive (inert). Explain your reasoning.
Ar = inert, 8 valence e- = filled valence e- level
K = reactive, 1 valence e-; loses 1 e- to obtain filled valence e- level

44. M M NM NM NM HW 2-2, #4,5 Ca, #20 Lose 2 e- Na, #11 Lose 1 e-
Cl, # Gain 1 e-
O, # Gain 2 e-
S, # Gain 2 e-
N, # Gain 3 e- M NM NM NM

45. NM M M HW 2-2, #4,5 P, #15 Gain 3 e- K, #19 Lose 1 e-
Al, # Lose 3 e- M M
2-2,#6: Metals LOSE e- to form + ions.
Nonmetals GAIN e- to form – ions.