Chapter 6 The Periodic Table and Periodic Law

1
Chapter 6The Periodic Table and Periodic Law
2
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

6
(No Transcript)
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
• Group B elements contained in the D block of the
  table
• Inner transition metals
• the lanthanide and actinide series
• F block

16
Nonmetals

• Generally a gas or a brittle, dull-looking solids
• Poor conductors
• Halogens7A
• 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
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.
• Oxygens 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 E 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.

33
(No Transcript)
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 E A S E 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 E A S E S