History of the atom theory

Timeline created by adiospopo11
In History
  • The Bombarding of Nagasaki and Fukushima

  • Period:
    -460 BCE
    to
    -370 BCE

    Democritus

    Held that everything is composed of ¨atoms¨ which are physically, but not, but not geometrically, indivisible.
  • Period:
    -384 BCE
    to
    -322 BCE

    Aristotle

    He thought that all the materials on Earth were not made of atmos, but for the four elements: fire, water, wind, and earth.
  • Period: to

    Lavioiser

    He was born in France Lavoisier found that mass is conserved in a chemical reaction. The total mass of the products of a chemical reaction is always the same as the total mass of the starting materials consumed in the reaction. His results led to one of the fundamental laws of chemical behavior: the law of conservation of matter, which states that matter is conserved in a chemical reaction.
  • Period: to

    Dalton

    British chemist John Dalton was born in Eaglesfield, England. Atoms of a given element are identical in mass and properties
    Compounds are formed by a combination of two or more different kinds of atoms.
  • Period: to

    Thompson

    He was born in Cheetham Hill, England, Thomson held that atoms are uniform spheres of positively charged matter in which electrons are embedded. Popularly known as the plum pudding model.
  • Period: to

    Plank

    Max Planck was a German scientist who first discovered that energy is emitted from a black body in discrete amounts called quanta. He showed that the amount of energy was proportional to the frequency of the radiation that was absorbed by the black body, a relationship now known as Planck's Law.
  • Period: to

    Rutherford

    He was born in Spring Grove, New Zealand. Rutherford proposed that an atom is composed of empty space mostly with electrons orbiting in a set, predictable paths around fixed, positively charged nucleus. I also discovered the proton.
  • Period: to

    Bohr

    He was born in Copenhagen, Denmark, The Bohr model of the atom, a radical departure from earlier, classical descriptions, was the first that incorporated quantum theory and was the predecessor of wholly quantum-mechanical models.
  • Period: to

    James Chadwick

    James Chadwick bombarded beryllium atoms with alpha particles. Unknown radiation was produced. Chadwick interpreted this radiation as being composed of particles with a neutral electrical charge and the approximate mass of a proton. This particle became known as the neutron. He was born in England.
  • Period: to

    Heisemberg

    He was born in Würzburg, Germany, contributed to atomic theory through formulating quantum mechanics in terms of matrices and in discovering the uncertainty principle, which states that a particle’s position and momentum cannot both be known exactly.