Timline

By bensb1
  • 500 BCE

    Democritus

    Democritus was born in Greece and was a rival of Aristotle and was the first person to develop an atomic theory, saying everything was made of tiny particles that were never destroyed, just changed and moved.
  • 400 BCE

    Aristotle

    Aristotle hypothesized that all matter was made up of some basic particles and how elements are transformed. He also created a criteria of purity to describe elements.
  • 800

    Abu Musa Jabir Ibn Hayyan Iran

    Born in modern-day Iran to a pharmacist. He has been dubbed the father of modern chemistry and developed precision instruments.
  • 1250

    Albertus Magnus

    Known as Albert the Great, was the first to isolate an element, arsenic. Because he was able to isolate arsenic, this created a desire in the chemistry world to find and isolate more elements.
  • 1440

    The Printing Press

    The Printing Press was originally invented by the Roman Empire by the German Johannes Gutenberg. Before the printing press, most European texts were printed by hand.

  • Vacuum Tube and the Electric Generator

    In Germany an early type of electric generator was invented. It was a sulfur ball inside of a wooden cradle. The electric generator made static electricity by applying friction to the sulfur ball. This was invented by Otto von Guericke, who also invented an air pump that allowed him to make a partial vacuum in a tube.

  • Robert Boyle

    In 1662, Boyle experimented and calculated his results leading to a discovery. This discovery was named Boyle's law where the volume of the gas varies inversely with pressure.

  • Henry Cavendish

    Contribution: First to recognize hydrogen gas as a distinct substance. He also described the composition of water and made the first accurate measurement of the density of the Earth.

  • Henry Cavendish

    In 1766 he discovered hydrogen, which at the time he called flammable air.

  • Precision Balance

    The precision balance is an important instrument used to compare the weights of multiple bodies of mass. It has become highly accurate and can produce trusted results up to the ten thousandths place.

  • Antoine Lavoisier

    Born in France Lavoisier proved the conservation of mass by weighing the end result of all the chemical reactions he studied. He also coauthored the modern system for naming new elements.

  • John Dalton

    He developed Dalton's law of Partial Pressure, Dalton's atomic Theory and his study of colorblindness led him to write a report that shed more light on what he called Daltonism. He also stated that he had no doubt that all gases could be liquefied provided their temperature was low and pressure high.

  • Amedeo Avagadro

    Avagadro was an Italian mathematical physicist who discovered what is now known as Avogadro's law that under controlled pressures and temperatures equal volumes of gas will have equal numbers of molecules.

  • Dmitri Mendeleev

    known for creating the periodic table of elements. After experimenting over and over he finally constructed a table where elements were ordered by their atomic number in horizontal rows he called groups and by properties in horizontal rows he called periods. Mendeleev had gaps in his table, but predicted that eventually new elements would be discovered and would will fill in the blank parts.

  • Ernest Rutherford

    Born in New Zealand Rutherford was a physicist and proposed the planetary atomic model. He concluded that atoms were largely empty space because many of the alpha particles that he shot at gold foil passed through undisturbed and a few got deflected

  • Marie and Pierre Curie

    Both Marie and Pierre Curie were Polish scientists who worked together in their science research. The Curies did research on the isolation of polonium. The Curies developed methods for the separation of radium from radioactive residues in sufficient quantities to allow for its characterization and the careful study of its properties.

  • William Ramsay

    He discovered argon, while he was trying to find something that was heavier than air. Argon then was used in light bulbs. While trying to find argon in uranium-bearing minera. He found out that there was another group to the periodic table of elements, the noble gases.

  • JJ Thomson

    Joseph John Thomson was an English physicist. Thomson discovered the electron by experimenting with a Crookes tube. He demonstrated that the cathode rays were negatively charged. He also experimented with positively charged particles in Neon Gas. His discovery and identification of the electron and the discovery of the first subatomic particle helped to revolutionize the knowledge of the atomic structure.

  • Niels Bohr

    Danish physicist, Niels Bohr, contributed to understanding the atomic structure and quantum theory. He won a Noble Prize on his research on the structure of the Atom. Bohr proposed a theory for the hydrogen atom based on the quantum theory that energy is transferred only in certain well defined quantities. The Bohr model the atom as a small, positively charged nucleus, surrounded by electrons travelling in circular motion around the nucleus.

  • Erwin Schrödinger

    Erwin Schrodinger was an Austrian physicist, who in the 1920’s developed a wave equation. This equation came as a result of his disliking of the quantum condition in Bohr's orbit theory. This work earned him a Nobel Prize in 1933, that he shared with Dirac. He learned all of this by observing physical representations of wave functions.

  • Lise Meitner

    Lise Meitner and Hahn discovered the first isotope of the element protactinium and she co-discovered nuclear fission. In 1922, Meitner discovered the Auger effect (radiation-less transition). She soon discovered too that there were no elements beyond uranium existed naturally.

  • Louis de Broglie

    Louis De Broglie was a French physicist best known for his work on the quantum theory and the wave nature of electrons. in 1929 he was awarded the Nobel prize for physics. the idea came from Einstein when he said that very short wavelength of light must behave like particles in some ways. this assumption gained acceptance when Broglie came forward with his theory about the duality matter

  • Werner Heisenberg

    Born in Germany in 1901. In 1927 he published his uncertainty principle which states that we can never know the exact position and velocity of a specific particle.

  • Irene Curie

    Discovered how to synthesize and artificially produce radioactive elements from stable elements. She produced radioactive nitrogen from boron as well as radioactive silicon from magnesium.

  • Linus Pauling

    In 1921 Linus Pauling suggested, and attempted to carry out, an experiment on the orientation of iron atoms by a magnetic field.

  • Linus Pauling

    Linus Pauling used the quantum theory and quantum mechanics in investigations of atomic and molecular structure and chemical bonding (the way atoms come together to form molecules) to understand and describe it. He published the structures of hundreds of inorganic substances like topaz and mica. In 1951, he also published the structure of the alpha helix.