Dillon+Crosby+Timeline


 * Chemistry Timeline ** ** Dillon Crosby **

** 450 AD And Prior **
 * ** Democritus - (ca. 460 BC - ca. 370 BC ) **
 * ** Democritus was a Greek Philosopher. **** Democritus said that everything is composed of atoms, which are physically indivisible but not geometrical indivisible. He also said that there is empty space between atoms and that atoms are indestructible. He decided that atoms are always in motion, there are infinite numbers of atoms, kinds of atoms, and that all atoms are different in size and shape. **** Democritus was also a Mathematician, anthropologist, biologist, and Cosmologist. (wiki) **


 * ** Empedocles - ( ca. 490 BC - ca. 430 BC ) **
 * ** Empedocles was a Greek Philosopher. **** Empedocles established the idea that there were four ultimate elements that everything was made up of, Fire (Heat), Air (Gas), Water (Liquid), and Earth (Solid). Empedocles connected these elements to the Greek Gods and Goddesses: Zeus, Hera, Nestis, and Aidoneus. **** Empedocles also studied Cosmo Genesis and ontology **


 * ** Aristotle - ( ca. 384 BC - ca. 322 BC ) **
 * ** Aristotle was a Greek Philosopher. **** Aristotle studied chemistry from Empedocles' ideas. In a way he was a student of Empedocles, and it shows in his work. He took Empedocles idea of the four ultimate elements, and expanded on it by adding a fifth element, Aether (Stars and Planets), a divine substance that makes up the heavenly spheres. **

** 450 - 1700 **
 * ** Hennig Brand - ( ca. 1630 - ca. 1710 ) **
 * ** Hennig Brand was a German Alchemist. **** Hennig searched for the "Philosopher's Stone". By attempting to use a bogus recipe of combining aluminium, potassium nitrate and urine, Hennig found phosphorus. **** Brand was also a merchant and an apprentice glass-maker. **


 * ** Sir Isaac Newton - (1642 - 1727 ) **
 * ** Sir Isaac Newton was a English Physicist. ** **Sir Isaac Newton is most well known for the discovery of gravity. However, Newton also made a number of other discoveries that would be later expanded upon by other scientists, such as the optics of color. These two examples are very closely related to atoms and magnetism, two very important aspects of chemistry.** ** Newton was also a mathematician, astronomer, natural philosopher, alchemist, and theologian. **


 * ** Robert Boyle - ( 1627 - 1691 ) **
 * ** Robert Boyle was a English/Irish Chemist, depending on who you get the information from. Boyle i ** **s known for discovering the connection between pressure on a fixed amount of gas, and the volume it takes up. As you double the pressure on the gas, the volume is cut in half, and vise versa. Robert Boyle was a** ** lso a natural philosopher physicist and inventor. **

** 1700 - 1800 **
 * ** John Dalton - ( 1766 - 1844 ) **
 * ** John Dalton was a English Chemist. ** **Dalton did a lot for the world of chemistry. He worked on research for ethylene and methane and the law of multiple proportions. This is the idea that there were specific interactions between atoms. He thought of the concept as solely physical. Dalton was also the first person to produce atomic weights. He wrote the first table of six elements: Hydrogen, Oxygen, Nitrogen, Carbon, Sulfur, and Phosphorus.** ** Dalton was also a meteorologist and a physicist **


 * ** Antoine Lavoisier - ( 1743 - 1794 ) **
 * ** Antoine Lavoisier was a French Chemist. ** **Antoine Lavoisier showed the world the effect of oxygen on certain metals that rust. More importantly he made discoveries that supported the law of conservation of mass by studying stoichiometry. Lavoisier carefully weighed the reactants and products during a chemical reaction and showed that the total mass before and after a chemical reaction stays the same.** ** Lavoisier was also a biologist. **


 * ** Joseph Proust - ( 1754 - 1826 ) **
 * ** Joseph Proust was a French Chemist. ** **Proust's greatest achievement in chemistry was finding the law of definite proportions. This law says that any chemical compound will have the same ratio of elements as you increase the mass.** ** Proust also liked grapes and honey. **

** 1800 - 1875 **
 * ** Dmitri Mendeleev - ( 1834 - 1907 ) **
 * ** Dmitri Mendeleev was a Russian Chemist. Mendeleev was the creator of the first periodic table of elements. Although there were elements missing, Dmitri predicted this and left spaces open in his table for later discoveries to fill. Dmitri Mendeleev was so honored that a crater on the moon, Mendeleev, and the element 101, Mendelevium (radioactive), were named after him. Dmitri Mendeleev was also a Physicist. **
 * ** Wilhelm Röntgen - ( 1845 - 1923 ) **
 * **Wilhelm Röntgen was a German Physicist. Röntgen discovered the ever important electromagnetic radiation at a specific wavelength. This range is called the X-ray. The range spans from 0.01 to 10** nano meters **, and can be used in useful applications such as checking for broken bones. Wilhelm was also a Mechanical Engineer.**


 * ** Michael Faraday - ( 1791 - 1867 ) **
 * ** Michael Faraday was an English Chemist. Faraday is known for a large number of things (mostly named after himself), as well as Electrochemistry and Electromagnetism. Laws on anodes, cathodes, electrodes, and ions were figured out by Faraday.He did not stick solely to magnetism however, he also closely researched chlorine and found a few new compounds between chlorine and carbon. Michael was also able to create new alloys of steel as well as optical glasses. The tool that would be perfected into the Bunsen Burner was also created by Faraday. Michael Faraday was also a Physicist and a Natural Philosopher. **

** 1875 - 1900 **
 * ** Henri Becquerel - ( 1852 - 1908 ) **
 * ** Henri Becquerel was a French Physicist. Becquerel did a lot of work with polarization of light. He found the connection between the recently discovered X-rays, and the glow coming from naturally occurring radiactive material. The radiaction coming from Uranium was not deflected by magnetic fields as X-rays were. **
 * ** Joseph John "J.J." Thomson - ( 1856 - 1940 ) **
 * **"J.J." Thomson was a British Physicist. Thomson was the creator of the mass spectrometer, the isotope, and most importantly, the electron. J.J. used the "plum-pudding model (below) to explain the presence of the electron. Joseph John Thomson was also a very good teacher.**

** 1900 - 1915 **
 * ** Robert Millikan - ( 1868 - 1953 ) **
 * ** Robert Millikan was an American Physicist. He was known for the discovery of the charge on an electron by use of the oil-drop experiment. The experiment used the gravitational pull on drops of oils that were suspended between two electrodes. Millikan studied at four colleges/Universities: University of Chicago, California Institute of Technology, Oberlin College, and Columbia University. **
 * ** Marie Curie - ( 1867 -1934 ) **
 * ** Marie Curie was a crazy polish physicist/Chemist. She was known, and died from, her famous discovery of Radioactivity. Marie studied radioactive isotopes and found two new elements, Polonium and Radium. Through a number of processes, Marie Curie would find the tiniest amounts of these radioactive elements in rock that she broke down chemically. She would carry around her discovered elements in her pocket, and eventually died of aplastic anemia due to her exposure. Marie Curie was the first women to receive the Nobel Prize. **
 * ** Ernest Rutherford - ( 1871 - 1937 ) **
 * **Ernest Rutherford was a British Physicist and Chemist. He was a very important part of chemistry. He discovered a number of very important things, such as the nucleus, which he displayed with his Rutherford Model. He also looked into radioactivity and found the alpha and beta rays. During research, Rutherford noticed that radioactive elements had a half-life, meaning that they would slowly deteriorate. Ernest came to obtain the title, "Father of Nuclear Physics". Ernest Rutherford was born in New Zealand.**

** 1915 - 1950 **
 * ** Niels Bohr - ( 1885 - 1962 ) **
 * ** Niels Bohr was a Danish Physicist. Bohr made himself known by studying, and improving, the ideas surrounding the structure of an atom, and [partially introducing quantum mechanics. The Bohr model, which was created by Bohr himself, was an improvement upon the Rutherford Model, an is sometimes referred to as the Rutherford-Bohr Model. Bohr also had a number of heated debates surrounding quantum mechanics with another founder, Albert Einstein. **


 * ** James Chadwick - ( 1891 - 1974 ) **
 * ** James Chadwick was an English Physicist. Chadwick was able to find the third component of an Atom, the Neutron. The neutron is a particle that contains neither a positive or negative charge, but no charge at all. Finding the neutron was necessary in using nuclear fission of Uranium to produce Gamma Rays. Although his is only known for one main thing, his discovery is very important. Chadwick was intern-shipped at the Ruhleben Prisoner of War Camp. **
 * ** Werner Heisenberg - ( 1901 - 1976 ) **
 * ** Werner Heisenberg was a German Physicist. He made his name in a number of different things, including the discovery of the uncertainty principle, Heisenberg's microscope, and matrix mechanics. Most importantly however, Werner was the last person to make any major changes to the Electron Cloud Model, and has been credited with the discovery of the model. **
 * ** Erwin Schrödinger - ( 1887 - 1961 ) **
 * ** Erwin Schrödinger was an Austrian Physicist. Erwin is known as one of the Fathers of Quantum Mechanics. His two main mains in his career were the Schrödinger Equation, and the Schrödinger's Cat Thought. The Schrödinger Equation is: **
 * Dependent of Time: **


 * Independent of Time: **

** 1950 - Present **
 * ** Murray Gell-Mann - ( 1929 - ) **
 * ** Murray Gell-Mann is an American Physicist. Gell-Mann set up the quark model, which dealt with Hadrons. Hadrons are are particles, including protons and electrons, where protons are the only ones that are stable and do not decay (exception: Electrons within atomic nuclei). He was also known for supporting the, at-the-time, unpopular string theory. Murray Gell-Mann was born into a Jewish family. **
 * ** George Zweig - ( 1937 - ) **
 * ** George Zweig is a Russian Physicist. He also worked on similar things as Gell-Mann did, but went about it in a slightly different manner. He introduced the quarks that Gell-Mann was using, and he also created the OZI Rule. **
 * ** Glenn T. Seaborg - ( 1912 - 1999 ) **
 * ** Glenn Seaborg was an American Chemist. He was responsible for the Trans uranium Elements. These are the elements with atomic numbers higher than 92. They are elements that are unstable and readily decay into the other elements radioactively. Not a lot has been found out with these elements compared to their stable counterparts, due to the unstable qualities. Five new trans Uranium elements have been found since Seaborg's death. **

** Electron Cloud Model ** ** The Electron Cloud model shows where the electrons of an atom can be at any point. It is called the electron cloud model, because when the many different positions that the electrons will be at an point are drawn into the model, their is complete chaos that will just look like a large cloud. This model was created with a combination of Rutherford, Bohr, and Heisenberg's work. Heisenberg was the last one to make changes to the concept, so the credit lies in his name. **

** Plum Pudding Model ** ** The Plum Pudding Model shows relationship between the nucleus and the electrons. The "pudding" is the blue sphere, shown above, that has a positive charge, and the "plums", the pink dots shown above, depict the electrons strewn about within the charge. J.J. Thomson was the creator of this model of the inner-workings of the atom. The model was first show in 1904, but was later dis-proven by the Rutherford Model, or Planetary Model. **

** Planetary Model ** ** The Planetary Model was a great find when it came to the world of the atom. The planetary model was created by Ernest Rutherford, after he discovered the hard compact object that is the Nucleus of an atom. During his famous Gold Foil Experiment, Rutherford noticed that alpha rays were bouncing at funny angles while coming into contact with a thin gold foil. This observation proved the presence of another object within the atom much larger than electrons. **

** Rutherford-Bohr Model **

** The Rutherford-Bohr Model was created as a better way to depict the newly discovered nucleus and its connection with its electrons. The model shows a positively charged nucleus in the center surrounded by orbitals of different degrees. The model shows the first orbital holding two of the electrons, and the next holding eight, and so on. The total number of electrons is equal to the number of electrons in the given element, and the number of electrons in the last ring is equal to the charge that the atom holds. The idea of the Rutherford-Bohr Model was a combination of the thoughts between Ernest Rutherford's Planetary Model, and Niels Bohr's new thoughts. **

** References ** **Resources** **[|NobelPrize.Org]** **[|The American Institute of Physics]** **[|Wikipedia]** **Images** **[|Democritus]** **[|Empedocles]** **[|Aristotle]** **[|Hennig Brand]** **[|Sir Isaac Newton]** **[|Robert Boyle]** **"John Dalton"** **[|Antoine Lavoisier]** **[|Joseph Proust]** **[|Dmitri Mendeleev]** **[|Wilhelm Röntgen]** **[|Michael Faraday]** **[|Henri Becquerel]** **[|Joseph John "J.J." Thomson]** **[|Robert Millikan]** **[|Marie Curie]** **[|Ernest Rutherford]** **[|Niels Bohr]** **[|James Chadwick]** **[|Werner Heisenberg]** **[|Erwin Schrödinger]** **[|Murray Gell-Mann]** **[|George Zweig]** **[|Glenn T. Seaborg]** **[|Plum Pudding]** **[|Rutherford-Bohr]** **[|Planetary Model]**
 * [|Electron Cloud]**