History of Atoms Timeline

By rhsharma@cisb.org.in
  • 460 BCE

    Democritus

    He theorized that all material bodies are made up of indivisibly small “atoms.” If you keep cutting an object, it will get to the size where you cannot cut it anymore.
  • 384 BCE

    Aristotle

    Aristotle said that the universe was made of water, fire, earth, air. Opposing the opinion of Democritus.

  • Antoine Lavosier

    Antoine Lavoisier examined the progressions that occurred when two synthetics responded and shaped another compound. He gauged the synthetics when the response, and he found the all out mass of the synthetic substances were equivalent to the compound that was delivered. Subsequent to doing likewise a couple of additional times, he reached the resolution that Matter is neither made nor obliterated during a compound response.- law of preservation of mass.

  • Joseph Proust

    Proust discovered that copper carbonate's components generally contained similar extents, regardless of the quantity used. This led to the law of distinct extents, stating that a substance compound contains similar components in the same mass extents.

  • Joseph Proust

    John Dalton discovered atoms and he came up with the atomic theory. He thought they atoms could not be broken down into smaller particles. He thought of them as solid, hard spheres.

  • J.J. Thompson

    J.J. Thomson revolutionized nuclear construction by revealing the electron through a cathode beam tube. A negative-charged terminal at the cathode and a positive-charged anode were used to test the nature of the ray. The ray was repulsed by a negative plate and pulled in by a positive plate, indicating it was made up of mass-bearing particles, later renamed electrons.

  • The Plum Pudding Model

    In 1904, J.J. Thomson concocted a model of the iota he called the plum pudding model. He realize that electrons were adversely charged, and that particles were unbiased, so he said that something needed to adjust the electron, which would need to be a positive substance in the iota. He portrayed the iota as a plum pudding, with adversely charged particles being encircled by emphatically charged "pudding."