Quote of the day

1
Quote of the day

• How far you go in life depends on your being
  tender with the young, compassionate with the
  aged, sympathetic with the striving, and tolerant
  of the weak and strong. Because someday in your
  life you will have been all of these.

2
The Periodic Table

• Theoretical Chemistry

3
Origin of Periodic Table

• Triads - groups of 3 elements with similar
  properties
• (Dobereiner 1817)
• Law of Octaves properties of elements repeat
  every 8 elements
• (Newlands 1863)

4
Origin of Periodic Table

• Dimitri Mendeleev 1869
• Properties of elements are periodic functions of
  their atomic masses.
• Developed 8 column table
• Left spaces for undiscovered elements
• Columns contained elements with similar
  properties
• Problems with Ni, I, K (Why?)

5
Origin of Periodic Table

• X-ray experiments by Mosley (1913) led to
  discovery of atomic numbers.
• Modern Periodic Law properties of elements are
  periodic functions of their atomic numbers.

6
Organization of Periodic Table

• Rows are called periods.
• Columns are called families or groups.
• All elements in a family have similar properties.
• Octet Rule elements with 8 valence electrons
  are unreactive

7

• The Periodic Table of Elements

The P.T. is made up of
Groups/Families (columns)
Periods (rows)
8
The groups are further categorized as follows
1
8
Main Group (A)
2
3
4
5
6
7
Group B
9

• The groups may also be broken down into

(including Hydrogen)
Non-Metals
Metals (not including Hydrogen)
10
Alkaline Earth
Noble Gases

• Each group is then further classified as follows

Metalloids
Alkali
Halogens
Transition Metals
Stair step
Inner Transition Metals
11

• The Inner Transition Metals are classified as
  follows

Lanthanides
Actinides