1. Chapter 6 The Periodic Table and Periodic Law

2. Development of the Modern Periodic Table
Section 6.1
Development of the Modern Periodic Table

3. Objectives
Trace the development and Identify key features of the periodic table.

4. History 1790s, French scientist Lavoisier 23 elements
1800s: electricity and spectrometer

5. John Newlands Patterns of the periodic table Law of octaves
Elements on the eights had similarities

7. Meyer & Mendeleev
1869-Meyer and Mendeleev: connection between atomic mass and properties
Mendeleev published it first
Left holes of undiscovered elements
Predicted properties of undiscovered elements- Sc, Ga, Ge

8. Moseley Problems with Mendeleev Rows by increasing atomic mass
Moseley used atomic number instead

9. The Periodic Law
There is a periodic repetition of chemical and physical properties of the element when they are arranged by increasing atomic number.

10. The Modern Periodic Table
Horizontal rows- periods
Vertical columns- groups or families

11. Groups 1A through 8A = Representative Elements
Wide range of chemical and physical properties
Groups 1B through 8B = Transition Elements

12. Metals shiny, smooth solid room temperature
good conductors of heat and electricity

13. Alkali Metals
Alkali Metals= 1A (excluding hydrogen)
highly reactive

14. Alkaline Earth Metals Alkaline Earth Metals= 2A
highly reactive (not as much as 1A)

15. Transitions Transition metals Inner transition metals
Group B elements contained in the D block of the table
Inner transition metals
the lanthanide and actinide series
F block

16. Nonmetals Halogens=7A Noble Gases= 8A
Generally a gas or a brittle, dull-looking solids
Poor conductors
Halogens=7A
REALLY REACTIVE
Noble Gases= 8A
unreactive and stable (all valence electrons are filled)

17. Metalloids
contain the physical and chemical properties of both metals and nonmetal

18. Homework
Section 6.1 Assessment
1-6 on page 158

19. Reactivity Trends Increases down the table for the metals
Decreases down the table for the nonmetals
                                                                                                                                        

20. Classification of the Elements
Section 6.2
Classification of the Elements

21. Objectives
Explain why elements in the same group have similar properties
Identify the four blocks of the periodic table based on electron configuration

22. Valance Electrons
The properties of each element in each group are similar because they have the same number of valence electrons

23. Valence Electrons and Period Number
Energy level of valence electrons = period on the table
Example: Lithium: period 2, valence electron in 2nd energy level (1s22s1)

24. Valence Electrons and Group Number
Group number (1A-8A) = number of valence electrons

25. Putting it Together Oxygen is in the 3rd period and in group 6A.
Oxygen’s valence electrons are located in the ____ energy level.
Oxygen has ___ valence electrons.

26. S,P,D, and F Blocks 4 different energy sublevels: s, p, d, and f
S block= 1A and 2A
holds max of 2 electrons
P block= 3A through 8A
max holds 6 electrons
S block must fill before P block can fill
Noble gases are stable because of filled S and P blocks

27. S,P,D, and F Blocks Continued…
D block = transition metals
max of 10 electron
F block= inner transition metals
unpredictable manner of filling
max of 14 electrons

28. Reactivity Trends Increases down the table for the metals
Decreases down the table for the nonmetals
                                                                                                                                        

29. Homework
Page 162, #10-15

30. Periodic Trends: Atomic Radius
For metals, atomic radius = ½ distance between adjacent nuclei in a crystal element
For nonmetals, atomic radius = ½ distance between nuclei of identical atoms that are chemically bonded

31. Periodic Trends: Atomic Radius
DECREASES I N C R E A S

32. Atomic Radius
The increase from top to bottom is due to adding electron shells.
The decrease from left to right is due to increased nuclear charge as you move to the right, which draws electrons closer to the nucleus.

34. Periodic Trends: Ionization Energy
Ionization energy= energy required to remove an electron from a gaseous atom
Octet rule = atoms tend to gain lose or share electrons to acquire a full set of 8 valence electrons

35. Periodic Trends: Ionization Energy
INCREASES D E C R A S

36. Periodic Trends: Electronegativity
Electronegativity= relative ability of an atom to attract electrons in a chemical bond.

37. Electronegativity
Arbitrary units called Paulings (after Linus Pauling) are used to express electronegativity.
Electronegativity increases from left to right across a period and from top to bottom down a group.

38. Periodic Trends: Electronegativity
INCREASES D E C R A S