atomic model

By weberjacob
  • 500 BCE

    The Alchemists

    he thought you could change any metal into gold
  • 442 BCE

    Democritus

    developed the atomic theory about the universe and the theory was anticipated for use in conservation of energy and irreducibility of matter.
  • 429 BCE

    Plato

    broke atoms down into shapes
  • 384 BCE

    Aristotle

    help create a knowledge of physics and astronomy

  • Robert Boyle

    his theory was anything that can be broken down into 2 or more parts is not an element

  • Lavoisier

    created law of conservation in mass

  • John Dalton

    his theory was that atoms were indivisible and indestructible building blocks While all atoms of an element were identical different elements had atoms of differing size and mass.

  • Dmitri Mendeleev

    Mendeleev found that, when all the known chemical elements were arranged in order of increasing atomic weight, the resulting table displayed a recurring pattern, or periodicity, of properties within groups of elements

  • Henry G.J. Moseley

    that the element is determined of the atomic number not atomic weight

  • The Curies

    Curie conducted her own experiments on uranium rays and discovered that they remained constant, no matter the condition or form of the uranium. The rays, she theorized, came from the element's atomic structure. This revolutionary idea created the field of atomic physics.

  • J.J. Thomson

    J.J. Thomson's experiments with cathode ray tubes showed that all atoms contain tiny negatively charged subatomic particles or electrons. Thomson proposed the plum pudding model of the atom, which had negatively-charged electrons embedded within a positively-charged "soup."

  • Werner Heisenberg

    Werner Heisenberg 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.

  • Albert Einstein

    Einstein also in 1905 mathematically proved the existence of atoms, and thus helped revolutionize all the sciences through the use of statistics and probability. Atomic theory says that any liquid is made up of molecules (invisible in 1905). Furthermore, these molecules are always in random, ceaseless motion

  • Robert Millikan

    during the 1890s the theory that electricity was conveyed by a miniscule unit, the electron, gained acceptance. By measuring how the various drops of oil moved about, Robert Millikan showed that their charge always was a multiple of a precisely determined charge - the electron's charge.

  • Ernest Rutherford

    Ernest Rutherford postulated the nuclear structure of the atom, discovered alpha and beta rays, and proposed the laws of radioactive decay. He received the Nobel Prize in Chemistry in 1908.

  • Niels Bohr

    In 1913, Niels Bohr proposed a theory for the hydrogen atom based on quantum theory that energy is transferred only in certain well defined quantities. Electrons should move around the nucleus but only in prescribed orbits. When jumping from one orbit to another with lower energy, a light quantum is emitted.