The History of the Atom

Democritus

400 BCE

Democritus contributed to the history of the atom because it was him who adopted and was given credit to for discovering the atomic theory. He hypothesized that matter was made up of tiny spheres that were indestructible and solid, but also invisible.

John Dalton

1800

Dalton’s contribution to the atomic theory is that he found all atoms in a element are in same mass and properties. He also found out compounds are made up two different atoms and he also found out chemical reactions are rearrangements of atoms. He discovered this while doing research on meteors and studying gases.

Joseph John Thomson

1904

Thomson’s contribution to the atomic theory is he discovered the electron, split an atom, and he created Plum Pudding Model. He discovered the electron when applying electricity to a vacuum.

Ernest Rutherford

1910

Rutherford’s contribution to the atomic theory is he created the Rutherford Model of the atom. He found out that the center or the nucleus was positive atoms and he found out that atoms are mostly empty space. He found this out by performing the gold foil experiment.

Niels Bohr

1913

Bohr contribution to the atomic theory is theory about the hydrogen atom and how it’s energy and wave lengths, he also developed the Bohr Model.