Atomic Theory Timeline Kyle, Justin, Mike

  • Published on
    19-Jan-2015

  • View
    24.515

  • Download
    2

Embed Size (px)

DESCRIPTION

History of the atom

Transcript

  • 1. Democritus Abdera 460-370 B.C. He first attempted to create materialism. Everything is composed of atoms .

2. Antione Lavoisier

  • 1772
  • Total mass of a product of a chemical reaction is always the same thing as the total mass
  • Conservation of mass

3. Law of Conservation of Mass

  • 1789
  • Matter can not disappear it can only be rearranged
  • At high speeds mass changes to energy

4. Joseph Louis Proust

  • 1798
  • Created the law of constant composition
  • Constant composition

5. Daltons Atomic Theory

  • 1799
  • Law of constant composition
  • Oxygen and Carbon combined make 2 compounds

6. John Dalton

  • 1803
  • Recorded the first tables of relative atomic mass
  • Atomic number

7. Law of Definite Proportions

  • 1805
  • Law say if formula AB is constant then the weight ratio will stay the same
  • Weight ratio stays the same

8. Dmitri Mendeleev

  • 1869
  • Created the periodic table
  • List of elements

9. Eugene Goldstein

  • 1886
  • Investigated X-rays
  • Discovered cathode rays

10. Erwin Schrodinger

  • 1887-1961
  • Created the Schrodinger Wave Equation
  • Used to describe behavior of electrons in atoms

11. Cathode Ray Tube

  • 1893
  • 2positive leads connected into a neon tube will make it light up
  • Electric makes light

12. J.J. Thompson

  • 1897
  • Discovered that cathode rays are small steams of atoms
  • An electron has a negative charge

13. Plum Pudding Atomic Model

  • 1897
  • He said that there has to be a positive and negative charge to balance out an atom
  • Atoms are neutral

14. Ernest Rutherford

  • 1898
  • Discovered and studied alpha particles and discovered the nucleus
  • Nucleus

15. Marie Curie

  • 1902
  • Discovered the radio active elements
  • Radio active elements

16. Rutherford Model

  • 1909
  • Model of a nucleus and electrons
  • Nucleus is in the center and the electrons orbit it

17. Robert Millikan

  • 1911
  • Made an oil drop experiment
  • Made electron have an electric charge

18. Bohr Planetary Model

  • 1913
  • He thought that electrons only orbit in one direction
  • They are called stationary orbits

19. Niels Bohr

  • 1913
  • Considered the term of stationary orbits for the electrons and that there is more than one level of orbit
  • Electron cloud

20. Henry Mosdeley

  • 1913
  • Numbered the elements
  • Order of elements

21. Quantum Mechanical Model

  • Mathematical equation developed by Schrodinger
  • Calculated where electrons are at any given moment

22. Gold Foil Experiment

  • 1920
  • It showed that the nucleus is positive and the electrons orbit it

23. James Chadwick

  • 1932
  • Found the neutron
  • His discovery led to nuclear fission and the atomic bomb

24. Lise Meitner

  • 1966
  • First discovered nuclear fission