Chemistry Timeline

  • 384

    Aristotle

    Aristotle
    384 - 322 B.C.
    He rejected Democritus's atomic theory because it didn't agree with his own ideas. He did not believe that the "nothingness" of empty space could exist. People started believing him rather than Democritus. The denial of the atoms existence went unchallenged for two thousand years.
  • 460

    Democritus

    Democritus
    460 - 370 B.C.
    He was the first person to propose the idea that matter was not infinitely divisivle. He believed there was small little particles called atoms that made up matter. He believed atoms couldn't be created, destroyed, or futher divided.
  • John Dalton

    John Dalton
    1766 - 1844
    Was a schoolteacher in Englad when he marked the beginning og the development of modern atomic theory. Dalton went over Democritus's ideas and changed somethings based upon the results of his on scienticic reseatch he conducted. He made his own theory called Dalton's atomic theory, keeping some of the things Democritus discovered that were right all along.
  • Antonie Lavosier

    Antonie Lavosier
    Compiled a list of elements known at the time. The list contained 23 elements.
  • Joseph Proust

    Joseph Proust
    Created elements of water. Made Proust's Law and also created gold.
  • Eli Whitney

    Patented the cotton gin which is a machine that separates seeds, hulls and other unwanted materials from cotton after it has been picked.
  • Amedeo Avagadro

    Amedeo Avagadro
    Theorized that equal volumes of gases at the same temperature adn pressure contain equal numbers of molecules. He also establised tha trelative molecular weights of any two gases are similar to the ratio fo the densities of the two gases under the constant conditions of temperature and pressure- known as the Avagadro Principle
  • Joseph Nicephore Niepce

    Joseph Nicephore Niepce
    Created the first photographic image with a camera obscura. The image requited eight hours of light exposure and later faded.
  • Charles Goodyear

    Charles Goodyear
    Goodyear accidentally heated a mixture of natural rubber and sulfer.The reaction made the rubber much stronger. The new rubber compound revolutionized the rubber industry and was eventually sed in the manufacturing of automobile tires.
  • Alexander Graham Bell

    Alexander Graham Bell
    Built the first telephone that transmitted electrically the human voice
  • William Crookes

    William Crookes
    Crookes was an English physicist. One day he noticed a flash of light within one of his tubes. The flast was produced by some form of radiation striking a light-producing coating tht had been appied to the enf o tthe tube. He did more work and it started showing rays traveling from the cathode to the anode within the tube. It became known as the cathode ray. He was also one of the first scientist to discover a fourth state of matter which is what we call Plasma today.
  • Henri Becquerel

    Henri Becquerel
    Showed that the rays emitted by uranium caused gases to ionize and taht they differed from x-rays in that they could be deflected by electric or magnetic fields.
  • J.J. Thomson

    J.J. Thomson
    Late 1890's Thomson proved Dalton's atomic theory to be wrong. Thomsom did experiments to determine the ratio of an atoms charge to its mass. He concluded that there were more particles smaller than the atom. Dalton was wrong because atoms were divisible into smaller subatomic particles.
  • Madame Curie

    Madame Curie
    discovered radioactive substance of radium and polonium. She coined the term radioactivity.
  • Albert Einstein

    Albert Einstein
    Explained that light energy cam in chuncks or quanta, called photons. He dicussed the Browian motion that helped in proving the existence of molecules. He also gave forrth explanation regaring the dynamics of individal moving bodies. He also explained the nature of space and time
  • Mary Anderson

    Mary Anderson
    Patented the windshield wipers
  • Robert Millikan

    Robert Millikan
    Determined the charge of an electron
  • Ernest Rutherford

    Ernest Rutherford
    He became interested in studying ohw positively charged alpha particles interact with solid matter. He studdied aplha particles and the deflections it made.
  • Henry Moseley

    Henry Moseley
    Discoverd that atoms of ech element contain a unique positive charge in tehir cuclei (atomic number)
  • Niels Bohr

    Niels Bohr
    Proposed a quantum model for the hydrogen atom. Bohr said that the hydrogen atom has only cetain allowable energy states.
  • Max Planck

    Max Planck
    Originated the quantum theory
  • Louis deBroglie

    Louis deBroglie
    Proposed an idea that eventually accounted for the fixed energy levels of Bohr's model.
  • Erwin Schrodinger

    Erwin Schrodinger
    Furthered the wave-particle theory proposed be de Broglie. He came up with an equation that treated the hydrogen atom's electron as a wave.
  • Werner Heisenberg

    Werner Heisenberg
    Published his uncertainty principle, which he built his philosophy and for he is best known .
  • Amelia Earhart

    Amelia Earhart
    Was the first female pilot to fly solo across the Atlantic Ocean.
  • James Chadwick

    James Chadwick
    Found that the nucleus contained another subatomic particle, a nuetral particle called the neutron.
  • Edwin Armstrong

    Edwin Armstrong
    invented frequency-moodulated or FM radio
  • Konrad Zuse

    Konrad Zuse
    Built the first freely programmable computer
  • Andrew Aford

    Andrew Aford
    Made the first maseter FM antenna system in the world deisigned to allow individual FM stations to broadcast simultaneously from one source on the Empire State Building in NYC
  • Barbara Askins

    patented a mthod of enhancing the pictures using radioactive materials. This helped with NASA and made improvemetns in x-ray technology and in the restoration fo old pictures.
  • Randice-Lisa Altschul

    Randice-Lisa Altschul
    Invented the worlds first disposable cell phone