Atomic History Timeline

Atomic History Timeline By: Jeffrey Fortin Mark Fraser

Table of Contents: • Ancient time- 450 A.D. , Demcritus, Thales, Leucippus • 1700- 1800, Sir Isaac Newton, • 1800 – 1875, John Dalton, Frederick Abel, • 1875 – 1900, Wihelm C. Roentgen, Marie Curie, J.J. Thomson • 1900 – 1915, Henri Bequerel, Erenest Rutherford, Erwin Schrodinger • 1915- 1950, Neils Bohr, Robert Milikan, Werner Hesienberg, James Chadwick • 1950 – present, Bertrand Russell, J. Robert Oppenheimher, Bernard T. Feld, Atomic history time line

Democritus • 460-370 bc • Was born in Abdera in Thrace • Backed up Leucippus theories, Atoms were invisible, and had matter • Also the only way to see Atoms is when they rearrange in a reaction Atomic history time line

Leucippus Around for the first half of the 5th century, he was the teacher of Democritus. He believed everything was composed of atoms. Leucippus has no writings that can be traced back to himself, but can be through Democritus. The only writing that can be traced back to him is: Nothing happens at random (marten), but everything from reason (ek logou) and by necessity. – Leucippus, Atomic history time line

Thales 624-546 BC – born at Miletus Through the understanding of the earth, Thales came up with water is the first principal. Also he discovered point ABC in a circle make special cases and can find the diameter of a circle. Atomic history time line

1700-1800 • Sir Isaac Newton • Antoine Lavoisier • Humphry Davy Atomic history time line

Sir Isaac Newton 1643-1727 Sir Isaac Newton laid the foundation of the atomic theory with the different attraction in the different stated atoms were in weather it was gas liquid or a solid. He also discovered calculus and the first three laws of motion. Atomic history time line

Antoine Lavoisier • 1743-1794 • Developed the first extensive list of elements • Reformed chemical nomenclature • Recognized oxygen and hydrogen • Discovered that mass may change shape or form, but the mass always stays the same Atomic history time line

Humphry Davy 1778-1829 Davy discovered alkali and alkaline earth metals. He is also credited with discovering chlorine and iodine. He invented the Davy work lamp which let miners work in gaseous areas. This scientist also discovered such elements as sodium potassium, calcium, magnesium, barium and boron. Atomic history time line

1800-1875 Frederick Abel John Dalton Jon Jacob Berzelius Atomic history time line

Frederick Abel • 1837- 1902 • Abel was a professor at the Royal Military Academy • He was appointed to Chemist of the War Department • Abel also invented Guncotton, which is a low order propellant which lead to the development of gun powder Atomic history time line

John Dalton 1866-1844 An English chemist who created the: Atomic Theory 1) All matter is made of atoms. Atoms are indivisible and indestructible. 2) All atoms of a given element are identical in mass and properties 3) Compounds are formed by a combination of two or more different kinds of atoms. 4) A chemical reaction is a rearrangement of atoms. This is what it looked like in His new system of chemical Philosophy Atomic history time line

Jons Jacob Berzelius 1779-1848 Berzelius came up with chemical notation and, along with Dalton, was considered one of the founders of modern chemistry. He also discovered new elements such as silicon, selenium, thorium, cerium, and lithium Atomic history time line

1875-1900 Wilhelm C Roentgen Marie Curie JJ Thomson Atomic history time line

Wilhelm C Roentgen 1845- 1923 He was a German Physicist who detected electromagnetic radiation in the wave lengths which is better known as the X-Ray Atomic history time line

Marie Curie 1867-1934 Madam Curie is known for her theory of radioactivity, and also for discovering two new elements, Radium and Polonium. She won many awards including the Nobel peace prize. She was also the first female professor at the university of Paris. Her life was unfortunately cut short bye a street car accident involving a horse drawn vehicle. Atomic history time line

JJ Thomson 1856-1940 He won the Nobel prize for his discoveries involving electrons and isotopes, along with his studies of the conductivity of electricity in gasses. He was knighted in 1908 and became the master of trinity college in 1916 were he continued to work until his death. Atomic history time line

1900-1915 • Herni Becquerel • Ernest Rutherford • Albert Einstein Atomic history time line

Herni Bequerel • 1852-1908 • Becquerel was a major contributor to the discovery of X-Rays and radioactivity • He was also the third in his family to occupy the chair at the museum national d’histoire Nuturella • Adding to his list of accomplishments, he was award the Nobel prize with Marie and Pierre Curie Atomic history time line

Ernest Rutherford 1871-1937 Known as the father of nuclear physics, he conducted the gold foil experiment which proved that the positively charged atoms were being deflected, some only a few degrees but a couple up to ninety degrees. This proved that there is a small, dense center in an atom known as the nucleus. He was awarded the Nobel peace prize for his outstanding work in the year 1908. Atomic history time line

Albert Einstein • 1879-1955 • He was a winner of the Nobel peace price and was a key player in the Manhattan Project, although he was opposed to use of the atomic bomb in war. • Einstein was also well known for his work involving the photoelectric effect, which can be described as when matter absorbs electron magnetic radiation, resulting in electrons being emitted from the object. Atomic history time line

1915-1950 • Niels Bohr • Werner Heisenberg • Erwin Schrodinger • James Chadwick Atomic history time line

Neils Bohr Life • 1885-1962 • He is know for the development of the atomic structure and quantum mechanics • He received the Nobel peace prize in 1922 • He also worked on the Manhattan project Atomic history time line

Werner Heisenberg 1901 -1976 He received his Nobel peace prize for setting forth the matrix formulation of quantum mechanics. He was involved with the Nazis and was in their “Uranium Club” Heisenberg was also in charge of the Reich Research Council. He was one of ten scientists that were arrested after WWII. He then settled in a British occupied zone in Germany and was the head of the Kaiser Wilhelm Institute For Physics. Atomic history time line

Erwin Schrodinger 1887-1961 He received the Nobel peace prize for his contributions in Quantum Mechanics. He also applied atoms to everyday life in his Schrodinger Cat Through experiment. He also published the Annals der Physiks paper which was considered one of the most important of the 20th century. Atomic history time line

James Chadwick • 1891- 1974 • He was award the Nobel peace prize in 1935 • He was awarded this for his discovery of Neutrons • He did a major part of his studies at Cambridge college Atomic history time line

1950- present • J. Robert Oppenheimer • Bernard T. Felds Atomic history time line

J. Robert Oppenheimer • 1904-1967 • The father of the Atomic Bomb • In 1954 during the Red Scare, Oppenheimer was revoked of his rights to write about physics, and his security clearance was revoked • When JFK was in office he was awarded the Enrich Fermi Award as a gesture of political rehabilitation Atomic history time line

Bernard T Feld “ I was involved in the original sin, and life atoning for it. - Bernard T. Feld” 1919-1993 He worked on the Manhattan Project but then was appointed to the international conceal to remove nuclear weapons form the world.Also worked at the Massachusetts Institute of Technology. “ I was involved in the original sin, and I have spent a large part of my life atoning for it. - Bernard T. Feld” Atomic history time line

Atomic Models • Small, sphereical, solid, indivisible model • Electron cloud model • Plum Pudding model • Rutherford-Bohr model • Planetary model Atomic history time line

Small, spherical, solid, indivisible model In early times, before the discovery of protons, neutrons, or electrons, popular belief was that the smallest partical of matter was a tiny, small, solid partial. Nothing else was known as far as the nucleus is concerned. Atomic history time line

Plum Pudding model The design was proposed by J.J. Thomson in 1906. The discovery of the nucleus had yet to be made, so naturally this component of the atom was lacking from Thompsons model. What he did include, however were “corpuscles,” Thompsons name for electrons, that he depicted as plums in his model. The pudding was a positively charged area of mass which balanced out the negative charge of his plum-like “corpuscles”. Atomic history time line

The planetary model of the atom • Developed by Neils Bohr, in his model the protons and neutrons are located in the small, dense nucleus, while the electrons orbit around them. The scale is disproportionate, however, because of the fact that the atomic radius is roughly 1000 times that of the nucleus Atomic history time line

Rutherford-Bohr model Developed by Ernest Rutherford and Neils Bohr, this model was an important step in understanding the structure of the atom. Rutherford's gold foil experiment led him to the discovery of the dense central region within a primarily entry space in each atom. He also concluded that since positively charged partials bounced back, the central region must have a positive charge. These two scientists created this model in such a way that the electrons travel around the nucleus in an orbit al fashion. There are different levels upon which these negatively charged partials travel. The further away from the nucleus, the more energy they have. Though not perfect by today’s standards, the model was a breakthrough at the time Atomic history time line

Electron Cloud Model Based upon the work of a number of scientists including Rutherford, Bohr, Heisenberg and Schrödinger, the Electron Cloud Model is a compilation of ideas. Rutherford's contribution is the small dense nucleus within a cloud. The electron cloud surrounding it is made up by ideas form Bohr and Heisenberg. Bohr had the idea that electrons moved around the nucleus while Heisenberg figured out that the only way to describe where they are is through probity distribution. His concept is involved in quantum mechanics where Schrödinger comes into play. The electron cloud is a region were the electrons could be found but doesn’t specify where they are. Atomic history time line

Bibliography • “Language of Physics.” Dictionary and Research Guide. 2001-2008 Enlexica. November 1, 2008. <http://www.123exp-science.com/t/01554053557/> • “Understanding Radiation in Your Life, Your World.” US Environmental Protection Agency. <http://www.epa.gov/rpdwebOO/understand/rutherford.html> • “The Cloud Model.” Science Joy Wagon. 1999 <http://www.regentsprpe.org/Regents/physics/phys05/catomodel/cloud.html> • “Who Came Up With The Electron Cloud Model of the Atom?” WikiAnswers. Answers Corporation 2008. <http://wiki.answers.com/Q/Who_came_up_with_the_electron_cloud_model_of_the_atom> • Wikimedia Foundation, Inc. <http://www.wikipedia.org/> Atomic history time line

Atomic History Timeline