# data[].attributes.body
What: Democritus introduced the atomic theory that stated the universe is composed of small particles known as atoms.
When: Democritus presented his theory in 442 B.C.E.
Where: In Ancient Greece

# data[].attributes.body
What: He proposed the Atomic Theory similar to Democritus' he stated that all atoms of the same element are the same shape, size, and mass. He also predicted that a chemical reaction is the rearrangement of atoms.
When: Dalton presented his theory in 1803
Where: Manchester, UK

# data[].attributes.body
What: He discovered the electron and proposed that atoms have sub-particles with positive and negative charges and that the charges present in equal amounts neutralizing the atom. His model was known as the Plum Pudding Model.
When: Joseph Thomson created his model in 1903
Where: Manchester, UK

# data[].attributes.body
What: Bohr predicted that the electron orbit the nucleus and that the energy of the orbit is related to size. He also predicted that radiation is absorbed or emitted when electrons move orbits. Also, he predicted that hydrogen has a positive nucleus surrounded by protons and neutrons with a negative electron cloud.
When: Bohr released his theory in 1913
Where: In Denmark.

# data[].attributes.body
What: Rutherford created the Planetary Model of The Atom. It described the atom as positively charged core known as the nucleus where the mass is concentrated. The nucleus orbits the negative constituents known as electrons.
When: Rutherford proposed this description in 1911.
Where: New Zealand

# data[].attributes.body
What: Schrödinger created the Electron Cloud Model which states that atoms do not orbit any nucleus instead they move in waves.
When: Schrödinger proposed his theory in 1926.
Where: Vienna, Austria