100 Greatest Discoveries - CHEMISTRY
1. Oxygen (1770s)
Joseph Priestley discovers oxygen; later, Antoine Lavoisier clarifies the nature of elements. Priestley produces oxygen in experiments and describes its role in combustion and respiration. Then, by dissolving fixed air in water, he invents carbonated water. Priestley, oblivious to the importance of his discovery, calls the new gas "dephlogisticated air." Lavoisier gives oxygen its name and correctly describes its role in combustion. Lavoisier then works with others to devise a chemical nomenclature, which serves as the basis of the modern system.
2. Atomic Theory (1808)
John Dalton provides a way of linking invisible atoms to measurable quantities like the volume of a gas or mass of a mineral. His atomic theory states that elements consist of tiny particles called atoms. Thus, a pure element consists of identical atoms, all with the same mass, and compounds consist of atoms of different elements combined together.
3. Atoms Combine Into Molecules (1811 onward)
Italian chemist Amedeo Avogadro finds that the atoms in elements combine to form molecules. Avogadro proposes that equal volumes of gases under equal conditions of temperature and pressure contain equal numbers of molecules.
4. Synthesis of Urea (1828)
Friedrich Woehler accidentally synthesizes urea from inorganic materials, proving that substances made by living things can be reproduced with nonliving substances. Until 1828, it was believed that organic substances could only form with the help of the "vital force" present in animals and plants.
5. Chemical Structure (1850s)
Friedrich Kekule figures out the chemical structure of benzene, bringing the study of molecular structure to the forefront of chemistry. He writes that after years of studying the nature of carbon-carbon bonds, he came up with the ring shape of the benzene molecule after dreaming of a snake seizing its own tail. The unusual structure solves the problem of how carbon atoms can bond with up to four other atoms at the same time.
6. Periodic Table of the Elements (1860s – 1870s)
Dmitry Mendeleyev realizes that if all of the 63 known elements are arranged in order of increasing atomic weight, their properties are repeated according to certain periodic cycles. He formulates the periodic table of the elements and predicts the existence of elements that have not yet been discovered. Three of those elements are found during his lifetime: gallium, scandium and germanium.
7. Electricity Transforms Chemicals (1807 – 1810)
Humphry Davy finds that electricity transforms chemicals. He uses an electric pile (an early battery) to separate salts by a process now known as electrolysis. With many batteries he is able to separate elemental potassium and sodium in calcium, strontium, barium and magnesium.
8. The Electron (1897)
J.J. Thomson discovers that the negatively charged particles emitted by cathode ray tubes are smaller than atoms and part of all atoms. He calls these particles, now known as electrons, "corpuscles."
9. Electrons for Chemical Bonds (1913 onward)
Niels Bohr publishes his model of atomic structure in which electrons travel in specific orbits around the nucleus, and the chemical properties of an element are largely determined by the number of electrons in its atoms' outer orbits. This paves the way to an understanding of how electrons are involved in chemical bonding.
10. Atoms Have Signatures of Light (1850s)
Gustav Kirchhoff and Robert Bunsen find that each element absorbs or emits light at specific wavelengths, producing specific spectra.
11. Radioactivity (1890s – 1900s)
Marie and Pierre Curie discover and isolate radioactive materials. After chemically extracting uranium from uranium ore, Marie notes the residual material is more "active" than the pure uranium. She concludes that the ore contains, in addition to uranium, new elements that are also radioactive. This leads to the discovery of the elements polonium and radium.
12. Plastics (1869 and 1900s)
John Wesley Hyatt formulates celluloid plastic for use as a substitute for ivory in the manufacture of billiard balls. Celluloid is the first important synthetic plastic and is used as a substitute for expensive substances such as ivory, amber, horn and tortoiseshell. Later, Leo Baekeland invents hardened plastics, specifically Bakelite, a synthetic substitute for the shellac used in electronic insulation.
13. Fullerenes (1985)
Robert Curl, Harold Kroto and Rick Smalley discover an entirely new class of carbon compound with a cage-like structure. This leads to the discovery of similar tube-like carbon structures. Collectively, the compounds come to be called buckminsterfullerenes, or fullerenes. The molecules are composed entirely of carbon and take the form of a hollow sphere, ellipsoid, tube or ring. Named for Richard Buckminster Fuller, the architect who created the geodesic dome, they are sometimes called "buckyballs" or "buckytubes."
100 GREATEST DISCOVERIES (2004)
by Discovery Channel
Scientists have transformed the way we think and live throughout the centuries. What are the most important scientific discoveries of all time? In no particular order, we present the top 100 in eight different categories:
Bill Nye "The Science Guy" hosts a new series that highlights the greatest scientific discoveries of all time, from the earliest time to the present day. The series features nine episodes: Evolution, Earth Sciences, Medicine, Physics, Astronomy, Chemistry, Genetics and Biology, plus a wrap up episode featuring the top 10 discoveries of all time. This is a fun and instructive series, with a lot of historical re-creations, archival footage, visits to interesting scientific research facilities and interviews with present-day scientists including several Nobel laureates - all presented with the flair and humor associated with television's "Science Guy" Bill Nye.
Kathryn Coombs/ imdb.com
Product Description, by Amazon.com
Join host Bill Nye as he recounts the 100 most important discoveries and explains how each one has had a hand in shaping the modern world. Evolution & Earth Sciences: From the discovery of the dinosaur-killing KT asteroid to Carl Linnaeus' still-used life form classification system to the groundbreaking theories of Charles Darwin, learn how intelligent life began on earth. Venture beneath our planet's crust for a look at the powerful geological forces that keep life on the move and adapting plate tectonics, earthquakes and super volcanoes. Medicine & Physics: With physician Andreas Vesalius's groundbreaking anatomical drawings in 1538, a new science was born. Witness the horror of a pre-anesthesia operating room, see how X-rays were discovered and meet the man who developed the first vitamin. Plus, learn how physicist Sir Isaac Newton developed his three laws of motion and travel inside the atom for an explosive look at Einstein's best-known theory. Astronomy & Chemistry: Copernicus first theorized that the Sun was the center of our solar system, but it took the work of Johannes Kepler to prove it. Learn why the universe is expanding and meet modern astronomers who gauge the likelihood of life "out there." Joesph Priestley initiated the study of chemistry in 1770 with the discovery of oxygen. Genetics & Biology: Gregor Mendel's work with pea plants pioneered the study of genetics, but it wasn't until the creation of the double helix DNA model that the field really began to take off. Hundreds of years before the first DNA test, "Micrographia" championed the use of microscopes and set the stage for the first major discovery in biology: microorganisms. Learn how the secret of the cell was solved and how starfish led to the development of stem cell research. Top Ten Discoveries: What are the 10 greatest scientific discoveries of all time? Find out which of the original 100 were voted by viewers as the most groundbreaking.