1. Mendeleev and Chemical Periodicity
Section 1 History of the Periodic Table
Chapter 5
Mendeleev and Chemical Periodicity
When elements were arranged in order of increasing atomic mass, similarities in their chemical properties appeared at regular intervals.
Periodic - repeating patterns

2. Moseley and the Periodic Law
Section 1 History of the Periodic Table
Chapter 5
Moseley and the Periodic Law
Moseley arranged elements according to atomic number, rather than atomic weight.
The Periodic Law - physical and chemical properties of the elements are periodic functions of their atomic numbers.

3. Periodicity of Atomic Numbers
Section 1 History of the Periodic Table
Chapter 5
Periodicity of Atomic Numbers

4. The Modern Periodic Table
Section 1 History of the Periodic Table
Chapter 5
The Modern Periodic Table
The Periodic Table - arrangement of the elements in order of their atomic numbers so that elements with similar properties fall in the same column, or group.

5. Periodic Table Overview
Visual Concepts
Chapter 5
Periodic Table Overview
Click below to watch the Visual Concept.
Visual Concept