Periodic Table of the Elements

Dimitri Mendeleev (1834 - 1907)

Element At. Weight mp (oC) D (g/mL) Oxide Chloride

Lithium 7 180 0.534 Li2O LiCl

Sodium 23 98 0.968 Na2O NaCl

Potassium 40 63 0.89 K2O RbCl

Rubidium 86 39 1.53 Rb2O RbCl

Cesium 133 28 1.93 Cs2O CsCl

Alkali Metals

Element At. Weight mp (oC) D (g/mL) Oxide Chloride

Beryllium 9 1287 1.85 BeO BeCl2

Magnesium 24 650 1.738 MgO MgCl2

Calcium 40 842 1.55 CaO CaCl2

Barium 137 727 3.51 BaO BaCl2

Radium (226) 700 5.5 RaO RaCl2

Alkaline Earth Metals

Mendeleev’s Periodic Table

Mendeleev’s Periodic Table

Mendeleev’s Periodic Table of 1872

Property Ekaaluminum Gallium

atomic mass 68 69.72

density (g/cm³) 6.0 5.904

melting point (°C) Low 29.78

oxide's formula

Ea2O3 (density - 5.5 g cm-3) (soluble in both alkalis and acids)

Ga2O3 (density - 5.88 g cm-3) (soluble in both alkalis and acids)

chloride's formula Ea2Cl6 (volatile) Ga2Cl6 (volatile)

Light - Wave or Particle

Isaac Newton (1643- 1727)Proponent of Light Particles

Christiaan Huygens (1629 – 1695)Proponent of Light Waves

Key Properties of Wave BehaviorInterference

Diffraction

Young’s Double Slit Experiment

Wave Nature of Light

Spectrum of White Light

Electromagnetic Spectrum

Photoelectric Effect

Einstein Millikan

Double Slit Experiment Revisited

Atomic Spectra

Hydrogen Helium Neon Mercury

Hydrogen Spectrum