Atomic Theory Timeline

By emmakelseyellanah
  • 400 BCE

    Democritus adopts atomic theory

    His mentor, Leucippus came up with the model first. His model was simply a round sphere
  • 370 BCE

    Democritus's death

  • Dalton finds out about the atomic theory

    Dalton's fascination with gases gradually led him to formally assert that every form of matter (whether solid, liquid or gas) was also made up of small individual particles.

  • Dalton's death

  • Thomson adopts atmoic theory

    He demonstrated that cathode rays were negatively charged.

  • Rutherford adopts atomic theory

    He demonstrated that the atom had a tiny heavy nucleus

  • Bohr adopts atomic model

    Depicts the atom as a small positively charged nucleus surrounded by electrons that travel in circular orbits around the nucleus.

  • Rutherford's death

  • Thompson's death

  • Bohr's death