Atomic Elements
The first "atomic theorists" we have any record of were two fifth-century BC Greeks, Leucippus of Miletus (a town now in Turkey) and Democritus of Abdera. Their theories were naturally more philosophical than experimental in origin. The basic idea was that if you could look at matter on smaller and smaller scales (which they of course couldn't) ultimately you would see individual atoms - objects that could not be divided further (that was the definition of atom). Everything was made up of these atoms, which moved around in a void (a vacuum). The different physical properties -- color, taste, and so on -- of materials came about because atoms in them had different shapes and/or arrangements and orientations with respect to each other.
Evolution of the Atomic Concept and the Beginnings of Modern Chemistry
All Atoms
Electronic Structure of Atoms
Theory of Atoms in Molecules
Shape Software
A Quantum Chromodynamics QCD Site
Atoms, Molecules, Water, pH
Ato
Simulated physics using virtual atoms
Dancing Atoms
Concerning Production of Elements and Plasmoids
mic Elements
Atoms, Molecules and Ions
Periodic Table of the Elements
Chemical Elements
A Visual Interpretation of the Table of Elements
The Pictorial Periodic Table
chem4kids
THE GREEK ELEMENTS
COMMON ELEMENTS ALPHABETICALLY
ATOMIC WEIGHTS OF THE ELEMENTS
The Periodic Table of Poetry
