Atomic Theory

  • 400


    Democritus theorizes that everything in the universe is composed of tiny particles named atoms
  • Law of Conservation of Mass

    States that mass is neither created nor destroyed
  • Antione Lavoiser

    Discovered oxygen molecule and came up with Law of Constant Composition
  • Law of Definite Proportion

    Proust stated that a chemical compound has the same amount proportions of elements
  • Joseph Luis Proust

    Published the law of definite proportion and this helped Dalton to propose his atomic theory
  • Dlatons Atomic Theory

    Provided explanations for concepts and ideas
  • Dmitri Mendeleev

    Made first periodic table based on atomic mass
  • Eugen Goldstein

    Discovered atoms have positive charges
  • J.J. Thompson

    Creates Plum Pudding Model and discovers electron
  • Cathode Ray Tube

    Used to find charge to mass ratio of an atom
  • Plum Pudding Model

    Considered that the inside of an atom was like raisin bread
  • Marie Curie

    Dicovered atoms were divisible
  • Robert Millikan

    Discovered unit of charge in an electron, positively charged atoms and the mass of an electron
  • Gold Foil Experiment

    Used by Ernest Rutherford to figure out what nucleus really looked like and disproved Plum Pudding Model
  • Rutherford Model

    Better model of atom because people had the components but didnt know how they fit
  • Ernest Rutherford

    Discovered that atons have central positive nucleus surrounded by negative electrons
  • Bohr Planetary Model

    Explain structure and actions of complex atoms
  • Niels Bohr

    Led to possible calculation of energy level and that light emission is from electrons moving in lower level
  • Henry Moseley

    Rearranged periodic table based on atomic number not atomic mass and new periodic table was better and allowed for progression of atoms
  • Erwin Schrodinger

    Learned how to find probability of where an electron is located in an orbital
  • Quantum Mechanical Model

    Explains the behavior of atoms in the atomic and subatomic realms
  • James Chadwick

    Discovered nuetron and led to discovery of fission and atom bomb
  • LIse Meitner

    Explained nuclear fission and modeled the nucleus