1. Periodic Table

2. History Antoine Lavoisier – Father of Modern Chemistry
1829 German J. W. Dobereiner Grouped elements into triads
Three elements with similar properties
Properties followed a pattern
The same element was in the middle of all trends
Not all elements had triads

3. Law of Octaves 1862 John Newlands developed Law of Octaves
The elements showed a repetition in their chemical properties after 8 elements
Used Atomic Weights but not actual values
Important because showed the first pattern of repeating properties

4. Julius Lothar Meyer
Meyer first table published 1864 containing 28 elements
Arranged in order of Atomic Weight and made a clear horizontal relationship
Allowed properties (valency) to outweigh Atomic Weight
Anticipated Mendeleev by years

5. Meyer Left gaps to denote unknown elements
Not willing to make predicitions
More focused on Physical properties not chemical properties
Bitter battle with Mendeleev
Lost to Mendeleev because of Mendeleev’s forceful ways

6. History
Russian scientist Dmitri Mendeleev taught chemistry in terms of properties
Mid 1800 – atomic masses of elements were known
Wrote down the elements in order of increasing mass
Found a pattern of repeating properties
Not first to develop system but his version had the strongest impact

7. Mendeleev’s Table
Grouped elements in columns by similar properties in order of increasing atomic mass
Found some inconsistencies - felt that the properties were more important than the mass, so switched order.
Found some gaps
Must be undiscovered elements
Predicted their properties before they were found

8. Dmitri Mendeleyev
Mendeleyev was known as the “Father of the Periodic Table”
DOB:
Created the first table on
Table had 70 elements
Used properties to set up table

9. Mendeleev
Distinguished from competitors by a devotion to, and love for, the individuality of the elements that went hand in hand with an intimate knowledge of their chemical characteristics
Focused on both physical and chemical properties

10. Mendeleyev Cont. Properties Used: Atomic Weight Melting Pts. Densites
He could only predict these properties
His work preceded chemical advances by 30 years
Produced his table 27 years before the first subatomic particle, the electron was discovered
Did not predict Noble Gases

11. Acceptance Mendeleev’s table received real acceptance in 1875
Discovery of Scandium, Germanium and Gallium showed Mendeleev’s predictions were correct.

12. “The elements were not being arranged to make a periodic table, but to fit the periodic table”

13. Meyer vs. Mendeleyev Julius Meyer (1830-1895)
Created a table that plotted:
Atomic Volume vs. Atomic Weight
Lost out to Mendeleyev
Published before Meyer
Final Table:
Atomic Weight vs. Valency
Table had 8 columns but was missing Noble Gases
Discovered 30 years later

14. Modern Russian Table

15. Spiral Periodic Table

16. Changing of Table
Henry Moseley ( ) – changed table in 1913 by increasing atomic number
Currently use this today
Glenn Seaborg – rare earth series from Actinium (89) up.
Minor Changes – inner transitional Lu & Lr replaced La & Ac
Bohr first linked Quantum Theory

17. Today’s Table

18. More History First Classified Groups: Gases Non-Metals Metals Earths
First Elements Discovered:
Carbon
Sulfur
Copper
Gold & Silver
Iron
Tin
Antimony
Mercury
Lead
Oxygen (1772)
First Classified Groups:
Gases
Non-Metals
Metals
Earths

19. The elements in the A groups are called the representative elements

20. Transition metals
The Group B elements

21. IA IIA IIIB IVB VB VIB VIIB VIIIB IIIA IVA VA VIA VIIA VIIIA IB IIB 1
Other Systems IA
IIA
IIIB
IVB VB
VIB
VIIB
VIIIB
IIIA
IVA VA
VIA
VIIA
VIIIA IB
IIB 1 2 13 14 15 16 17 18 3 4 5 6 7 8 9 10 11 12 1A 2A 3A 4A 5A 6A 7A 8A 3B 4B 5B 6B 7B 8B 1B 2B

22. Vertical Columns Known as Groups or a Family
Elements in same group have similar physical & chemical properties
Each group is identified by a group number and group letter

23. Horizontal rows are called periods
There are 7 periods

24. Group 1A are the alkali metals
Group 2A are the alkaline earth metals

25. Group 7A is called the Halogens
Group 8 are the noble gases

26. The group B are called the transition elements
These are called the inner transition elements and they belong here

28. Metals

29. Metals & Their Properties
Metals are good conductors of heat and electricity
Metals are malleable
Metals have high luster

30. Example of Metals
Copper is a relatively soft metal and a very good electrical conductor
Mercury is the only metal that exists as a liquid at room temperature

31. Non-metals

32. Nonmetals & Their Properties
Carbon, the graphite in a pencil is an example of a nonmetallic elements
Nonmetals are poor conductors of electricity
Can be brittle
Non-lustrous
Many are gases at room temperature

33. Example of Nonmetals Sulfur was once known as Brimstone
Microspheres of phosphorus, a reactive nonmetal

34. Metalloids or Semimetals
Properties of both
Semiconductors

35. Example of a Metalloid Silicon is a metalloid
Silicon is brittle like a nonmetal
Silicon has metallic luster
Silicon is a semiconductor of electricity