Periodic Table and Periodic Trends

📋 Course Outline

1. Historical Development of the Periodic Table
2. Modern Table Structure and Classification
3. Blocks and Element Families
4. Periodic Arrangement and Electron Configuration
5. Atomic and Ionic Radii
6. Ionization Energy
7. Electron Affinity and Electronegativity
8. Period Three Reactions and Bonding
9. Oxides, Chlorides, and Oxidation States

📅 Key Dates

1. 1829Döbereiner grouped elements into triads of three elements with similar properties, in which the atomic weight of the middle element was roughly the average of the other two.
2. 1864John Newlands arranged 62 known elements in increasing atomic mass and observed that every eighth element resembled the first in properties.
3. 1869Dmitri Mendeleev arranged 63 elements by increasing atomic mass, left gaps for undiscovered elements, and accurately predicted their masses and properties.
4. 1913Moseley used X-ray emission to determine exact atomic numbers and rearranged the elements by atomic number, leading to the modern Periodic Law.