Atomic Theory



Approx. 500 BC

Plato created another theory based on the idea that explained that all things were made of 4 elements, which were earth, wind, fire, water and univers. He related this concepts with tetrahedron, octahedron, icosahedron, cube, and dodecahedron.


Approx. 450 BC

Democritus created a theory, which was based on the idea of atoms, the smallest indivisible, invisibles and eternal thing that formed all tangible things.

John Dalton

Approx. 1808

John continued the theory of atoms, but adding and re-making things. The theory was based on these facts:
-The matter is made of atoms.
-Every chemical element has the same atoms but different from anothers.
-Every compound is made of the unity from different elements, always the same type and proportion

Ernest Rutherford

Approx. 1871

Ernest Rutherford said that particles were made of protons, electrons and neutrons, and they had positive and negative charges.

Joseph John Thompson

Approx. 1897

Thompson created a new atom model, the "cookie model", based on a ball with many balls inlaid.

Werner Heisenberg

Approx. 1901

Niels Bohr

Approx. 1913

Niels Bohr added that there was a nucleos, in which orbits electrons.