Evolution of atomic theories

By andreapuebla
  • 400 BCE

    Democritus

    Democritus
    Democritus’ atomic theory posited that all matter is made up small indestructible units he called atoms.

  • Dalton

    Dalton
    Name: Billiard Ball
    Experiments with gases that first became possible at the turn of the nineteenth century led John Dalton in 1803 to propose a modern theory of the atom based on the following assumptions. 1. Matter is made up of atoms that are indivisible and indestructible.