Chem Unit 1

  • 400 BCE


    Democritus argued that everything was made of small particles called atomos; these were pieces of pure substances.
  • 350 BCE


    Aristotle argued that everything was made up of 4 elements: air, earth fire, water. This view was accepted for a long time because he was popular.
  • 1267

    Roger Bacon

    Roger Bacon
    Roger Bacon succesfully reproduced gunpowder; he was the first European to recreate it. He recorded it in his Opus Majus ~1267
  • Period: 1561 to

    Sir Francis Bacon

    Bacon (yum) supported the use of inductive logic for naturalistic study.
  • Robert Boyle

    Robert Boyle
    Boyle wrote The Skeptical Chymist and supported the admitting of doubt in order for the designing and testing of experiments. He proposed the existence of more than 4 elements and wrote The Skeptical Chymist in 1661
  • Antoine Lavoisier

    Antoine Lavoisier
    Lavoisier compiled the first chemistry textbook (Traité élémentaire de chimie) and developed the Law of Conservation of Mass.
  • Period: to

    Justus von Liebig

    Liebig developed a method to separate elements in natural compounds by combustion.
  • Period: to

    Joseph Proust

    Proust developed the law of definite proportions by noting that copper carbonate always had the same proportions of carbon, oxygen, and copper.
  • Alessandro Volta

    Alessandro Volta
    Volta made the first electric battery by stacking acid soaked flannel between alternating copper and zinc disks.
  • John Dalton

    John Dalton
    Dalton developed the 5 parts of the Atomic Theory based on Lavoisier's work.
  • Dmitri Mendeleev

    Dmitri Mendeleev
    Mendeleev organized the first periodic table.
  • Eugene Goldstein

    Eugene Goldstein
    Goldstein found that atoms have + charge and - charge potential via experimentation with a Crooks tube.
  • Antoine Henri Bacquerel

    Antoine Henri Bacquerel
    Bacquerel placed potassium uranyl sulfate onto photographic plates and wrapped in black paper, expecting it to absorb the sun's energy and emit it as an x-ray. It was overcast, yet the plates developed images. He had discovered radioactivity.
  • J.J Thomson

    J.J Thomson
    Thomson discovered electrons, which are subatomic particles, via cathode ray tube; disproving the part of Dalton's theory that stated atoms were the smallest pieces of matter. He also developed the plum pudding atom model.
  • Marie and Pierre Curie

    Marie and Pierre Curie
    The Curies compared the energy of pure uranium to uranium ore and found that uranium ore had more energy. Therefore, there were other radioactive elements in it. They then discovered radium and polonium.
  • Robert Millikan

    Robert Millikan
    Millikan calculated the electrical charge in an electron via oil drop experiment.
  • Period: to

    Ernest Rutherford

    Rutherford disproved Thomson's atomic model via gold foil experiment. He also stated that atoms are mostly empty space, discovered protons, and proposed the existence of neutrons.
  • Henry Moseley

    Henry Moseley
    Moseley Tested and proved the theory that the atomic number was the charge amount in an atom's nucleus by blasting electrons at elements. Furthermore, he found that the number of protons was the basic difference between elements.
  • James Chadwick

    James Chadwick
    Chadwick discovered neutrons via blasting alpha particles at beryllium atoms.