Atomic theory

Atomic theory

1. Democritus

   • Democritus created the first concept of atom
     • Smallest particle
       • indivisible

2. Dalton

   • Took the bases of democritus and reworked the theory
     • Chemical reaction is a rearrengement of atoms
       • Compound is a union of two atoms
         • discovered the electron by several tests

3. Rutherford

   • Discovered holes between atoms
     • proposed a positive mass in the center of the atom
       • electrons were kept on the atom because of the positive charge (protons

4. Bohr

   • Electrons move in a fixed position around the nucleus in different levels
     • The shells were greater the further they were from the nucleus
       • electrons can move up or down the shells if energy is applied

5. Eshrodinger

   • electrons are not in a fixed place, and it's impossible to define the exact location of the electron
     • Invented the "electron cloud" which showed the probabilty of the electron being in that place

6. Chadwick

   • Quantum mechanical theory
   • Found the neutron on the atom
     • Bombarded beyllium atoms with some alpha particules and radiation with neutral charge came as a result, demonstreating the neutrons