1. I. Development of the Modern Periodic Table (p. 174 - 181)
Ch. 6 - The Periodic Table & Periodic Law
I. Development of the Modern Periodic Table (p )

2. A. Mendeleev Dmitri Mendeleev (1869, Russian)
Organized elements by increasing atomic mass
Elements with similar properties were grouped together
There were some discrepancies

3. A. Mendeleev Dmitri Mendeleev (1869, Russian)
Predicted properties of undiscovered elements

4. B. Moseley Henry Moseley (1913, British)
Organized elements by increasing atomic number
Resolved discrepancies in Mendeleev’s arrangement
This is the way the periodic table is arranged today!

5. C. Modern Periodic Table
Group (Family)
Period

6. 1. Groups/Families Vertical columns of periodic table
Numbered 1 to 18 from left to right
Each group contains elements with similar chemical properties

7. 2. Periods Horizontal rows of periodic table
Periods are numbered top to bottom from 1 to 7
Elements in same period have similarities in energy levels, but not properties

8. 3. Blocks Main Group Elements Transition Metals
Inner Transition Metals

9. 3. Blocks Overall Configuration Lanthanides - part of period 6
Actinides - part of period 7

10. II. Classification of the Elements (pages 182-186)
Ch. 6 - The Periodic Table
II. Classification of the Elements (pages )

11. A. Metallic Character
Metals
Nonmetals
Metalloids

12. 1. Metals Good conductors of heat and electricity
Found in Groups 1 & 2, middle of table in 3-12 and some on right side of table
Have luster, are ductile and malleable

13. a. Alkali Metals Group 1 1 Valence electron Very reactive
Electron configuration
ns1
Form 1+ ions
Cations
Examples: Li, Na, K

14. b. Alkaline Earth Metals
Group 2
Reactive (not as reactive as alkali metals)
Electron Configuration
ns2
Form 2+ ions
Cations
Examples: Be, Mg, Ca, etc

15. c. Transition Metals Groups 3 - 12
Reactive (not as reactive as Groups 1 or 2), can be free elements
Electron Configuration
ns2(n-1)dx where x is column in d-block
Form variable valence state ions
Cations
Examples: Co, Fe, Pt, etc

16. 2. Nonmetals Not good conductors
Found on right side of periodic table – AND hydrogen
Usually brittle solids or gases

17. a. Halogens Group 17 (7A) Very reactive Electron configuration ns2np5
Form 1- ions – 1 electron short of noble gas configuration
Anions
Examples: F, Cl, Br, etc

18. b. Noble Gases Group 18 Unreactive, inert, “noble”, stable
Electron configuration
ns2np6 full energy level
Have a 0 charge, no ions
Examples: He, Ne, Ar, Kr, etc

19. 3. Metalloids Sometimes called semiconductors
Form the “stairstep” between metals and nonmetals
Have properties of both metals and nonmetals
Examples: B, Si, Sb, Te, As, Ge, Po, At

20. B. Chemical Reactivity Alkali Metals Alkaline Earth Metals
Transition Metals
Halogens
Noble Gases

21. C. Valence Electrons Valence Electrons
e- in the outermost energy level
Group #A = # of valence e- (except He) 1A 2A
3A 4A 5A 6A 7A 8A

22. C. Valence Electrons Valence electrons =
electrons in outermost energy level
You can use the Periodic Table to determine the number of valence electrons
Each group has the same number of valence electrons 1A 2A
3A 4A 5A 6A 7A 8A

23. D. Lewis Diagrams Ex: Chlorine Also called electron dot diagrams
Dots represent the valence e-
Ex: Sodium
Ex: Chlorine
Lewis Diagram for Oxygen