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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
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
Compiled a list of elements known at the time. The list contained 23 elements. -
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
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
Created the first photographic image with a camera obscura. The image requited eight hours of light exposure and later faded. -
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
Built the first telephone that transmitted electrically the human voice -
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
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
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
discovered radioactive substance of radium and polonium. She coined the term radioactivity. -
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
Patented the windshield wipers -
Robert Millikan
Determined the charge of an electron -
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
Discoverd that atoms of ech element contain a unique positive charge in tehir cuclei (atomic number) -
Niels Bohr
Proposed a quantum model for the hydrogen atom. Bohr said that the hydrogen atom has only cetain allowable energy states. -
Max Planck
Originated the quantum theory -
Louis deBroglie
Proposed an idea that eventually accounted for the fixed energy levels of Bohr's model. -
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
Published his uncertainty principle, which he built his philosophy and for he is best known . -
Amelia Earhart
Was the first female pilot to fly solo across the Atlantic Ocean. -
James Chadwick
Found that the nucleus contained another subatomic particle, a nuetral particle called the neutron. -
Edwin Armstrong
invented frequency-moodulated or FM radio -
Konrad Zuse
Built the first freely programmable computer -
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
Invented the worlds first disposable cell phone -
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.
