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Atomic Theory

By King_Kane2
  • 460 BCE

    Democritus

    Democritus
    Democritus was born in Abdera, Greece, around 460 BC. He was the first to theorize that all matter was composed of particles he later called Atoms. He came to this conclusion after taking a seashell and breaking into smaller pieces until it could no longer be broken. This discovery was important as it was the beginning of a long journey of further studies and scientific achievements.

  • John Dalton

    John Dalton
    Dalton was born in Eaglesfield, United Kingdom on September 6, 1766. Dalton proposed atomic theory, that atoms are indivisible, indestructible, and tiny spheres. After experimenting with different gases he came to the conclusion that every element has it's own atomic mass.

  • J.J. Thomson

    J.J. Thomson
    Thomson was born and raised in Cheetham Hill, Manchester, United Kingdom on December 18, 1856. In 1897 Thomson built a small scale particle accelerator with Cathode ray tubes, that were air tight. Through this experiment he discovered electrons. This led to the conclusion that atoms were composed of these subatomic particles. This also led to Thomson creating the Plum Pudding model in 1904, which is one of the first models of the Atom.

  • Ernest Rutherford

    Ernest Rutherford
    Rutherford Brightwater, New Zealand on August 30, 1871. Rutherford used the Gold Foil experiment to probe a positively charged nucleus with positively charge alpha particles. This led to him discovering Protons.

  • Niel Bohr

    Bohr was born and raised in Copenhagen, Denmark on October 7, 1885. Bohr proposed his quantized shell model of the atom to explain how electrons can have stable orbits around the nucleus Without interacting with the nucleus.

  • Erwin Schrodinger

    Erwin Schrodinger
    Erwin Schrodinger was born and raised Erdberg, Vienna, Austria on August 12, 1887. Schrodinger mathematical equations to describe the likelihood of finding an electron in a certain position. This led him to concluding that electrons act as waves that have a probable location.

  • James Chadwick

    James Chadwick
    Chadwick was born on October 20, 1891, in Bollington, United Kingdom. Chadwick In 1930, discovered that Beryllium, when swarmed by alpha particles, emitted a very strange stream of radiation. This led to him discovering that atoms were composed of more than just protons. This led to the discovery of Neutrons. This also led to him creating the quantum mechanical model of the atom.