2. What is the periodic table?
compact way of organizing elements
contains lot of information
allows one to make predictions about behavior & properties of elements
Elements

5. History of the Periodic Table
End of 1700’s – less than 30 elements known
Many elements discovered during 1800’s

7. John Newlands 1864: Law of Octaves
elements arranged by atomic mass
their properties repeat every 8th element
Law of Octaves
did not work for all known elements
Key idea was correct: Properties of elements do repeat in periodic way

8. Mendeleev & Meyer 1869: Mendeleev produced 1st accepted PT
elements ordered by ↑ atomic mass into columns with similar properties
Predicted existence & properties of undiscovered elements
Not totally correct
more accurate atomic mass calculations showed some elements not in right place

10. Remember 1860’s: No subatomic particles yet discovered
Dalton’s billiard ball model of the atom

11. 1913 – Henry Moseley By 1913, protons & electrons discovered
neutrons were predicted
determined atoms of each element contain unique # protons (= atomic number)
rearranged Mendeleev’s PT by atomic # instead of atomic mass
problems with elements in wrong place disappeared

12. Periodic Law
periodic repetition of chemical & physical properties of elements when are arranged by ↑ atomic number

13. Glenn Seaborg: 1950’s
Lanthanide and Actinide Series

16. Newlands
Seaborg
Mendeleev
Mosley

17. Vocabulary of the PT

18. Columns called groups or families
Today: #1 thru 18, Arabic numerals
Past: A & B groups, Roman numerals
A-Group
Columns 1,2,13-18
# IA – 8A
B-Group
Transition metals (columns 3-12)
# IB - 8B

19. Rows called series or periods
#1 thru 7

20. Column numbering (1  18) left to right
Period numbering (1  7) top to bottom

21. Structure of the Periodic Table
Closely related to electron configuration

22. Energy Levels = Row Number
Elements in same row have same # of energy levels
# of principal energy levels = to row #

23. Going Across Row 2: 2-8 Ne 18 (VIIIA) 2-7 F 17 (VIIA) 2-6 O 16 (VIA)
2-5 N
15 (VA)
2-4 C
14 (IVA)
2-3 B
13 (IIIA)
2-2 Be
2 (IIA)
2-1 Li
1 (IA)
Configuration
Element
Family

24. Going Down Column 1: 2-8-18-32-18-8-1 Fr 7 2-8-18-18-8-1 Cs 6 Rb 5 K 4
2-8-1 Na 3
2-1 Li 2 1 H
Configuration
Element
Period

25. Number of Valence Electrons
Elements in same column have same # valence electrons 4
14 or IVA 3
13 or IIIA 2
2 or IIA 1
1 or IA
Number of Valence Electrons
Group

26. Valence Electrons Chemical behavior determined by # valence electrons
Elements with same # valence electrons have similar chemical properties
Elements in same column have similar chemical properties

27. Classifying the Elements
2/3 of elements are metals
Remaining are non-metals and metalloids (semi-metals)
Metalloids have some properties of metals & some properties of nonmetals
Staircase:
dividing line between metals & nonmetals
elements to left are metals (except H)
elements to right are non-metals

28. Properties of Metals malleable – pounded into sheets
ductile – drawn into wires
have Luster
good conductors of heat & electricity
solid at room temperature (except Hg)
metals lose electrons to form positive ions “Metals are losers”
Low ionization energy
Low electronegativity

29. Properties of Nonmetals
gas or solid (except Br2)
solids are brittle
solids are dull
poor conductors of heat & electricity
nonmetals gain electrons & form negative ions
“Nonmetals are winners”
High ionization energy
High electronegativity
Properties are OPPOSITE of metals

30. Properties of Metalloids
5 on right side staircase: B,Si,As,Te,At
2 on left side staircase: Ge,Sb
Each metalloid has some metallic and some nonmetallic properties
Example:Si
shiny like metal but brittle like nonmetal

31. Names of Families (AKA group A elements)
Group 1 = Alkali Metals
Group 2 = Alkaline Earth Metals
Group 13 = Boron family
Group 14 = Carbon family
Group 15 = Nitrogen family
Group 16 = Oxygen family
Group 17 = Halogens
Group 18 = Noble Gases

32. Transition Metals Groups 3 through 12
AKA group B elements
Actinide and Lanthanide series = inner transition elements
Transition elements put the COLOR in your life
form brightly colored salts/solutions

33. Elements that are gases at STP
Diatomics:
H2, N2, O2, F2, Cl2
Monatomics: noble gases
He, Ne, Ar, Kr, Xe, Rn

34. Elements that are liquids at STP
Br2 (non-metal) and Hg (metal)

35. All other elements are solids at room temperature