First Definition of the Atom
Atomic Structure Discovered
Discovery of the Electron
The Nucleus
The Bohr Model
The Quantum Concept
Atomic Spectra
Bohr's Theory
Allowed Orbits
Radiationless Orbits
Quantum Jumps
Quantum Mechanics
Matter Waves
Wave Mechanics
The Quantum Mechanics Model
Electron Configuration
A Closer Look: The Quark