1. 1 DEOMCRITUS Dan Higgins

2. 2 DEMOCRITUS 460-370 BC First to believe the Atom was a solid sphere. That these atoms are attached together to make an object

3. 3 Disagree Other scientist like Plato and Aristotle disagreed with Democritis and his idea on Atoms. Did not believe spheres could connect to create an object

4. 4 John Dalton http://web.buddyproject.org/web017/web017/images/atom.JPG http://media-2.web.britannica.com/eb-media/21/8421-004-6101E314.jpg

5. 5 Dalton’s Personal Life Born a Quaker on 9/6/1766 in Cumberland, England Taught at a Quaker boarding school from ages 12-22 Colorblind, wrote a major paper on the matter for the Manchester Literary and Philosophical Society, “Daltonism” Became a physicist and chemist http://www.dkimages.com/discover/previews/783/868600.JPG

6. 6 Dalton’s Major Discovery Dalton’s 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. *Also calculated atomic weights from percentage of compositions in compounds http://www.hcc.mnscu.edu/chem/V.07/Daltons_atomic_theory_1.jpg

7. 7 By Scott Waldron p6

8. 8 Personal Life Born and raised in London Began an apprenticeship with Sir Humphry Davy in 1812 Died in 1867

9. 9 Scientific Career Mostly known as a physicist Helped invent many modern technologies including the motor Was the first scientist to pass electricity through a substance to separate elements Aforementioned process called electrolysis

10. 10 Dmitri Mendeleev - Born January 27, 1834 - Russian chemist - Acknowledged as being the creator of the first version of the periodic table of elements - Mendeleev predicted element properties that had not yet been discovered -Also worked in meteorology, geology, explosives and physics

11. 11 Dmitri Mendeleev Fun Facts - Did a lot of research on gas expansion - Introduced the metric system to the Russian empire - Created a smokeless gunpowder - Called "pyrocollodion" - Responsible for working with molecular weights to come up with the dilution formula for % alcohol in vokda - 2 water molecules : 1 ethyl alcohol molecule

12. 12 G.J. Stoney Ireland, 1874 Coined the term “electron” –Determined that there was a negative unit of electricity –J.J. Thomson, 1897 Corpuscles http://www.iscan.ie/spotlight/spotlight.htm

13. 13 Stoney (continued) Also in 1870s –Bronx becomes part of New York City –Elephant is first used for Republican Party Frankenstein, 1831 –Society fascinated by electricity and science New discoveries; possibilities seemed endless Science at the time –Atom was thought to be a solid sphere Had mass but no charge Early History of Atom http://images.google.com/imgres?imgurl=http://www.sc iencemuseum.org.uk/images/object_images/535x535/ 10312949.jpg&imgrefurl=http://www.sciencemuseum.o rg.uk/images/I044/10312949.aspx&h=400&w=535&sz =41&hl=en&start=5&um=1&usg=__P2upkSRAgAFakk meARKOUI8s9iM=&tbnid=6Vt9M1mlxB4I0M:&tbnh=99 &tbnw=132&prev=/images%3Fq%3Ddalton%2527s%2 Batom%26um%3D1%26hl%3Den%26sa%3DN Dalton’s Wooden Models of the Atom

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17. 17 Wilhelm Conrad Röntgen By Denisse Huezo-Rosales

18. 18 Important Facts Born March 27, 1845 at Lennep in the Lower Rhine Province of Germany When he was three his family and him moved to Apeldoorn in the Netherlands He went to the Institute of Martinus Herman van Doorn, a boarding school In 1862 he entered into a technical school at Utrecht but then he was unfairly expelled because he was accused of drawing a cartoon of a teacher when someone else had done it Then he began to study physics in college which is where he success started to develop

19. 19 The Discovery of X-Rays On the evening of November 8, 1895, he found that, if the discharge tube is enclosed in a sealed, thick black carton can exclude all light Basically he used this image first on his wife’s hand as he observed it he noticed the shadows of her bones, the shadow of the ring on her finger, and the penumbra of her flesh In further experiments, Röntgen showed that the new rays are produced by the impact of cathode rays on a material object. Because its nature was then unknown, he gave them the name X-rays

20. 20 1898 Ernest Rutherford By: Emily Petrie http://www.accessexcellence.org/AE/AEC/CC/images/ruther.460.gif

21. 21 Background Information Born August 30, 1871 in New Zealand. When he was 16, he went to Nelson Collegiate School and received a scholorship. After that, he went to University of New Zealand and Cantebury College.

22. 22 Accomplishments Offered a teaching job at McGill University, Montreal. During his time there, he published 69 papers on radiation. He researched radiation there and experimented with it.

23. 23 Known for: In 1898, he created and found three types of “rays”: alpha, beta and gamma rays. Alpha and beta are particle rays. Gamma is a high energy ray. http://www.accessexcellence.org/AE/AEC/CC/images/ruther.460.gif

24. 24 Sources http://scienceworld.wolfram.com/biography/rutherford.html http://www.nobelprize.org/nobel_prizes/chemistry/laureates/1908/run terford.htmlhttp://www.nobelprize.org/nobel_prizes/chemistry/laureates/1908/run terford.html http://www.physics.mcgill.ca/museum/ernest_rutherford.htm http://www.accessexcellence.org/AE/AEC/CC/images/ruther.460.gif

25. 25 Henri Bequerel 1896 Discovered natural radioactivity

26. 26 Radioactivity  He investigated to see if there was a connection between x-rays and natural occurring phosphorescence.  His father left him a supply of uranium salts, which give off phosphorescence when exposed to light.  He placed the salts, or ions, near to a photographic plate covered with opaque paper and the plate turned fogged.  This discovery was concluded to be a property of the uranium atom.  Henri showed that the rays that uranium gave off caused gases to ionize.  They were different from x-rays because t hey could be deflected by electric or magnetic fields.  He got a Nobel Prize Prize for physics in 1903.

27. 27 J.J. Thomsom 1897 Discovered the electron

28. 28 “Plum Pudding Model” “Pudding” represents the positive electricity The bits on “plum” represent the electrons There are no protons in the model http://www.youtube.com/watch?v=IdTxGJjA4Jw

29. 29 Mme. Curie Marie (Sklodowska) Curie Born November 7, 1867 Married fellow scientist, and physics professor Pierre Curie in 1895 Won the Nobel Prize for Physics in1903 Died in 1934 from radiation poisoning nobelprize.org/nobel_prizes/chemistry/laureates/

30. 30 Scientific Discoveries Worked with radioactive material Worked with Husband Was able to remove to separate radioactive material Study properties of radioactive material in depth Isolated Polonium and Radium http://upload.wikimedia.org/wikipedia/commons/thumb/1/13/Electron_shell_088_Radium.svg/558px- Electron_shell_088_Radium.svg.png http://upload.wikimedia.org/wikipedia/commons/thumb/2/27/Electron_shell_084_Pol onium.svg/558px-Electron_shell_084_Polonium.svg.png nobelprize.org/nobel_prizes/chemistry/laureates/

31. 31 Soddy 1877 - 1956

32. 32 Soddy Studied radioactivity at Glasgow University In 1913, he discovered the concept of isotopes: –certain elements exist in two or more forms which have different atomic weights but which are indistinguishable chemicals

33. 33 Definition of Isotopes One of two or more atoms having the same atomic number but different mass numbers.

34. 34 Planck 1858-1954

35. 35 Planck Planck's earliest work was on thermodynamics He studied the distribution of energy in the spectrum of full radiation Planck was able to figure the relationship between the energy and the frequency of radiation This was a major discovery in physics –E=Hv – Much of his research helped Einstein create the atom bomb

36. 36 The Planck law gives the intensity radiated by a blackbody as a function of frequency (or wavelength). Planck was also a philosopher of science. In his Scientific Autobiography and Other Papers, he stated Planck's Principle, which holds that – "A new scientific truth does not triumph by convincing its opponents and making them see the light, but rather because its opponents eventually die and a new generation grows up that is familiar with it." energy did not flow in a steady continuum, but was delivered in discrete packets Planck later called quanta. That explained why, for example, a hot iron poker glows distinctly red and white.

37. 37 Born March 14th, 1879 Wanted to teach Math and Physics, but couldn’t find the job Worked at a patent office, where he produced much of his work, including the mass energy equivalence equation, E=mc^2 Became extremely succesful scientist, producing the Theory of Relativity, winning the Nobel Prize of Physics in 1921, and many other achievements http://nobelprize.org/nobel_prizes/physics/laureates/1921/einstein-bio.html Albert Einstein

38. 38 E=mc 2 Einstein developed the mass-energy equivalence equation equation in 1905 E = energy, m = mass, c = speed of light Shows that when atom is converted into energy, it still produces a large amount of energy despite it’s small mass Based on the facts that: –Laws of physics are the same in all inertial frames –Speed of light is constant in all inertial frames

39. 39 E=mc 2 explained by Einstein http://www.youtube.com/watch?v=CC7Sg41Bp-U http://en.wikipedia.org/wiki/Image:Relativity3_Walk_of_Ideas_Berlin.JPG

40. 40 Hans Geiger 1882-1945 Became an assistant to the British physicist Earnest Rutherford in 1907 and that Is where he invented the Geiger counter http://www.notablebiographies.com/images/uewb_05_img0296.jpg

41. 41 The Geiger Counter Detected radioactive particles When an alpha particle is emitted from the radioactive atom as it passes through the tube it records it by clicking The Geiger counter showed the level of radioactivity by how much it clicked as the atom passed through

42. 42 Ernest Rutherford Gold Foil Experiment By, Mike Cox

43. 43 Gold Foil Experiment Marsden found that some alpha rays were scattered directly backwards, even from a thin film of gold foil. http://www.youtube.com/watch?v=Q8RuO2 ekNGw&feature=relatedhttp://www.youtube.com/watch?v=Q8RuO2 ekNGw&feature=related

44. 44 Rutherford Experiment -In 1911, Rutherford found out almost all the mass of an atom is in the nucleus. - Nucleus is so small it would take over five million of them side-by-side to cross a full top of a piece of paper -The Nucleus is one thousand times smaller than the atom it self.

45. 45 Henry Gwyn-Jeffries Moseley Discovered the concept of the atomic number (number of protons in the atom), 1913-1914 Killed during WWI fighting at Gallipoli, in 1915 http://www.experiencefestival.com/a/Henry_Moseley_-_Biography/id/5121944 http://www.csvt.qc.ca/patriotes/sciences/scp4/photos_m1/11moseley.gif

46. 46 Moseley built upon the earlier work of his teacher, Ernest Rutherford, who had made an atomic model in 1911. Moseley studied the location of positive charges in the atom. The atomic number is now included in the periodic table of elements, where before atomic weight was used. Moseley found that lines in the x- ray spectrum (illustration of wavelength) of each element moved the same amount each time the atomic number was increased by one Structure of atom http://www.necel.com/en/faq/ele2.gif Moseley’s Work

47. 47 The most difficult task that Moseley had was getting the equipment to work so as to give reliable data Moseley focused on finding a linear relationship between the atomic number and a measurable property of the nucleus The square root of the frequency’s value moves up the same amount for each one unit jump in the atomic number http://dbhs.wvusd.k12.ca.us/webdocs/AtomicStructure/AtNum-Moseley.html http://videos.howstuffworks.com/hsw/5790-henry-moseleys-periodic-table-video.htm

48. 48 Niels Bohr (1885-1962) Proposed atomic model that is accepted today –Atom has multiple orbiting outer shells w/ electrons –Aka “planetary model” Won Nobel Prize - 1922 http://web.gc.cuny.edu/sciart/copenhagen/nyc/images/Bohr.jpg http://www2.lucidcafe.com/lucidcafe/library/95oct/nbohr.html

49. 49 Bohr’s Atomic Structure - 1913 Based on Rutherford’s model + nucleus with - electrons orbiting around it Bohr’s theory: electrons travel in orbits that get larger as positioned further from the nucleus Outer orbits hold more electrons than inner ones determine atom’s chemical prop’s. http://wind.cc.whecn.edu/~mechalke/chapter5/nucleus3gif.gif

50. 50 Other Biographical Info. Denmark -> Sweden in fishing boat Helped develop atomic bomb (Eng. and U.S.) - Los Alamos Stressed its power & danger –Asked UN to prohibit nuclear weapons –Won U.S. Atoms for Peace award http://dimdima.com/Science/science_common/show_science.asp?q_aid=116&q_title=Niels+Bohr

51. 51 Erwin Schrödinger “I know not whence I came, nor whither I go, nor who I am.”

52. 52 Dead and Alive Schrödinger’s Cat Schrödinger’s Equation

53. 53 Atomic Structure Electron Clouds Wave Mechanics

54. 54 Lise Meitner 1878 - 1968 By Rachel Howell

55. 55 Research Was part of a science team with Otto Hahn and Fritz Strassmann Researched and came to an understanding of fission researched the relationship between beta and gamma radiation She was head of the Physics department of the Kaiser Wilhelm Institute

56. 56 Later Life In 1992, element 109 was named Meitnerium (Mt) in her honor Studied physics while world war two was going on. She had to flee to Sweden when Germany came into Austria because she was a Jew Hahn received the Nobel prize for his physics research in fission but Meitner was ignored