Atomic Timeline

Democritus

400

460 B.C.- 370 B.C.
A Greek philosopher that created the idea of the atom.
was not able to put date in B.C. years. http://www.perseus.tufts.edu/GreekScience/Students/Marc/short_paper.html

Atomic Timeline

Period: 400 to Nov 12, 2000

Isaac Newton

Nov 12, 1704

1643-1727
Proposed the ideas of atoms after democritus in 1704. He decribed our world as "A mechanical universe where small solid masses were in motion", which also gave his idea that atoms stay in motion. http://www-gap.dcs.st-and.ac.uk/~history/Mathematicians/Newton.html

John Dalton

Nov 12, 1803

1766-1844
He proposed the first Atomic Theory and introduced the first model of the atom called the Billiard Ball model. This name was given becuased he viewed the atom as a soild ball. He also found that atoms of the same element are identical, but atoms of different elements are different by their physical and chemical properties. http://web.lemoyne.edu/~giunta/dalton.html

Michael Faraday

Nov 12, 1832

1791-1867
An English scientist who contributed to the fields of electromagnetism and electrochemistry. He studied the effect of electricity on solutions, coined term "electrolysis" as the splitting of molecules with electricity, and developed the laws of electrolysis. http://www.chemteam.info/Chem-History/Faraday-Chlorine-1823.html

Julius Plücker

Nov 12, 1859

1801-1868
He was a German mathematician and physicist. He built one of the first cathode ray tubes which later lead to the discovery of the electron. http://www.britannica.com/EBchecked/topic/464998/Julius-Plucker

Dmitri Mendeleev

Nov 12, 1869

1837-1907
He was a Russian chemist and inventor. He discovered Periodic law by arranging all the known elements into 7 groups with similar properties. He then discovered that the properties of elements were periodic functions of the their atomic weights which he organized into a famous diagram call the periodic table. http://www.famousscientists.org/dmitri-mendeleev/

James Clerk Maxwell

Nov 12, 1873

1831–1879
He was a Scottish mathematical physicist. He helped the atomic feild by proposing that electric and magnetic fields filled the void of an atom. This is known as the theory of electromagnetic radiation. http://www.clerkmaxwellfoundation.org/html/who_was_maxwell-.html

Sir William Crookes

Nov 12, 1879

1832 –1919
He was a British chemist and physicist who worked on spectroscopy. He discovered the properties of cathode rays, some of his observations were that the rays traveled in straight lines, caused glass to fluoresce, imparts a negative charge to objects they strike, deflects by electric fields and magnets to suggest a negative charge, and causes pinwheels in their path to spin indicating they have mass. http://www.britannica.com/EBchecked/topic/143944/Sir-William-Crookes

Eugen Goldstein

Nov 12, 1886

1850–1930
He was a German physicist who was an early investigator of discharge tubes, the discoverer of anode rays, and is sometimes credited with the discovery of the proton. http://chemed.chem.purdue.edu/genchem/history/goldstein.html

George Johnstone Stoney

Nov 12, 1894

1826 –1911
He was an Anglo-Irish physicist. He is most famous for introducing the term electron as the "fundamental unit quantity of electricity". Although he had introduced the concept, he didnt introduced the word. http://www.rds.ie/index.jsp?a=806&n=245&p=182

Wilhelm Roentgen

Nov 12, 1895

1845-1923
He was a German physicist. Using a cathode ray tube he observed that nearby chemicals glowed. Further experiments found very penetrating rays coming from the cathode ray tube that were not deflected by a magnetic field. He named them Röntgen rays, today known as X-Rays. http://www.nobelprize.org/nobel_prizes/physics/laureates/1901/rontgen-bio.html

Henri Becquerel

Nov 12, 1896

1852-1908
He was a French physicist. While studying the effect of x-rays on photographic film, he discovered some chemicals spontaneously decompose and give off very pentrating rays. This is when he discovered the effects of radiation. http://www.physics.isu.edu/radinf/cuire.htm

Joseph John Thomson

Nov 12, 1897

1856-1940
He was an English physicist. He showed that cathode rays were composed of a previously unknown negatively charged particle, and is credited with the discovery of the electron. He is also credited with finding the first evidence for isotopes of a stable element as part of his exploration into the composition of canal rays. He also invented the mass spectrometer. http://www.chemheritage.org/discover/online-resources/chemistry-in-history/themes/atomic-and-nuclear-structure/thomson.aspx

Ernest Rutherford

Nov 12, 1898

1871-1937
He was a New Zealand-born British physicist who became known as the father of nuclear physics. He discovered the concept of radioactive half-life, proved that radioactivity involved the transmutation of one chemical element to another, and also differentiated and named alpha and beta radiation. http://www.rutherford.org.nz/

Marie Sklodowska Curie

Nov 12, 1898

1867-1934
She was a Polish and naturalized-French physicist and chemist who conducted pioneering research on radioactivity. She studied uranium and thorium and called their spontaneous decay process "radioactivity". She and her husband Pierre also discovered the radioactive elements polonium and radium. http://www.nobelprize.org/nobel_prizes/chemistry/laureates/1911/marie-curie-bio.html

Frederick Soddy

Nov 12, 1900

1877 -1956
He was an English radiochemist. He explained that radioactivity is due to the transmutation of elements, now known to involve nuclear reactions. He also observed spontaneous disintegration of radioactive elements into variants he called isotopes and discovered "half-life", which made initial calculations on energy released during decay. http://www.nobelprize.org/nobel_prizes/chemistry/laureates/1921/soddy-facts.html

Max Planck

Nov 12, 1900

1858–1947
He was a German theoretical physicist who originated quantum theory. He used the idea of quanta (discrete units of energy) to explain hot glowing matter. http://www.nobelprize.org/nobel_prizes/physics/laureates/1918/planck-bio.html

Hantaro Nagaoka

Nov 12, 1903

1865-1950
He was a Japanese physicist and a pioneer of Japanese physics during the Meiji period. He postulated a "Saturnian" model of the atom with flat rings of electrons revolving around a positively charged particle. http://link.springer.com/chapter/10.1007%2F978-3-540-70626-7_10

Richard Wilhelm Heinrich Abegg

Nov 12, 1904

1869-1910
He was a German chemist and pioneer of valence theory. His valence theory was that inert gases had a stable electron configuration which lead to their chemical inactivity. http://www.britannica.com/EBchecked/topic/1010/Richard-Wilhelm-Heinrich-Abegg

Albert Einstein

Nov 12, 1905

1879-1955
Hev was a German theoretical physicist and philosopher of science. He developed the general theory of relativity and the mass- energy equivlance formula E = mc. These achivements helped to establishing quantum theory. http://www.aip.org/history/einstein/

Hans Geiger

Nov 12, 1906

1882-1945
He was a German physicist. He is responciple for discovering the nucleus of an atom. He is also known as the co-inventor of the Geiger counter and took part of the Geiger–Marsden experiment, both which lead him to his discovery. http://www.nobelprize.org/nobel_prizes/physics/laureates/1990/press.html

Robert Andrews Millikan

Nov 12, 1909

1868-1953
He was an American experimental physicist who was known for his work on finding the measurement of the elementary electronic charge and for his work on the photoelectric effect. He found the mesurement of the charge and mass of a electron using a experiment called the oil drop experiment. http://www.nobelprize.org/nobel_prizes/physics/laureates/1923/millikan-bio.html

Ernest Rutherford

Nov 12, 1911

1871-1937
This is Rutherford's later achivement in the atomic feild. He managed to prove that most of an atom is empty space and that the nucleus is ery dense,very small and positively charged. These results were accepted by his gold foil experiment. http://www.rutherford.org.nz/

Henry Gwyn Jeffreys Moseley

Nov 12, 1914

1887-1915
He was an English physicist. Using x-ray tubes, he determined the charges on the nuclei of most atoms and is responciple for the deffination of the atomic number of an element. http://www.famousscientists.org/henry-moseley/

Francis William Aston

Nov 12, 1919

1877-1945
He was a British chemist and physicist. He discovered the existence of isotopes through the use of a mass spectrograph. http://www.nobelprize.org/nobel_prizes/chemistry/laureates/1922/aston-bio.html

Niels Henrik David Bohr

Nov 12, 1922

1885-1962
He was a Danish physicist who made foundational contributions to understanding atomic structure and quantum theory. He made a atomic model that had atoms built up of sucessive orbital shells of electrons. http://www2.lucidcafe.com/lucidcafe/library/95oct/nbohr.html

Louis de Broglie

Nov 12, 1923

1892 -1987
He was a French physicist who made groundbreaking contributions to quantum theory. He discovered that electrons had a dual nature-similar to both particles and waves. This was called particle/wave duality, which supported Einstein's observations. http://www.nobelprize.org/nobel_prizes/physics/laureates/1929/broglie-bio.html

Werner Karl Heisenberg

Nov 12, 1927

1901-1976
He was a German theoretical physicist and one of the key pioneers of quantum mechanics. He described atoms by means of formulas connected to the frequencies of spectral lines. He is also credited with the Principle of Indeterminancy which states that "you can not know both the position and velocity of a particle at the same time". http://www.aip.org/history/heisenberg/p01.htm

Erwin Rudolf Josef Alexander Schrödinger

Nov 12, 1930

1887-1961
He was a Austrian physicist who developed a number of fundamental results in the field of quantum theory. He was one of the first to view electrons as continuous clouds and introduced "wave mechanics" as a mathematical model of the atom. http://www-history.mcs.stand.ac.uk/Biographies/Schrodinger.html

Paul Adrien Maurice Dirac

Nov 12, 1930

1902-1984
He was an English theoretical physicist who made fundamental contributions to the early development of both quantum mechanics and quantum electrodynamics. Eventhough he didnt find any anti-particles, he was still the first to proposed the idea. http://www.nobelprize.org/nobel_prizes/physics/laureates/1933/dirac-bio.html

James Chadwick

Nov 12, 1932

1891-1974
He was an English physicist that is popular for the discovery of the neutron. http://www.nobelprize.org/nobel_prizes/physics/laureates/1935/chadwick-facts.html

Glenn Theodore Seaborg

Nov 12, 1941

1912-1999
He was an American scientist who is famous for his involvement in the synthesis, discovery, and investigation of ten transuranium elements. His work in this area also led to his development of the actinide concept and the arrangement of the actinide series in the periodic table of the elements. http://www.nobelprize.org/nobel_prizes/chemistry/laureates/1951/seaborg-bio.html

Enrico Fermi

Nov 12, 1942

1901-1959
He was an Italian physicist. He is known for his work on Chicago Pile-1, the first nuclear reactor, as well as for his contributions to the development of quantum theory, nuclear and particle physics, and statistical mechanics. http://www.osti.gov/accomplishments/fermi.html