History of the atom theory

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

  • Period:
    -460 BCE
    -370 BCE


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


    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


    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


    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

    Johann Wolfgang Döbereiner

    German chemist whose observation of similarities among certain elements anticipated the development of the periodic system of elements.
    During the 1820s Döbereiner’s experiments with the ignition of hydrogen on contact with powdered platinum led the Swedish chemist J.J. Berzelius to develop the concept of catalysis. Toward the end of the decade, Döbereiner found that the properties of bromine, a liquid, seem halfway between those of chlorine gas and the solid iodine.
  • Period: to


    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


    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


    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


    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


    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.