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Honors Chem 3.3 & 21
| Question | Answer |
|---|---|
| Democtritus | 400 BC- atom concept |
| George Bauer | 1500s ore |
| Philippus Theophrastus Bombastras von Hohenheim | 1500s medicine |
| Berzelius | late 1700s (alchemy) symbols for elements |
| George Stahl | 1600 phlogiston |
| Antoine Lavoisier | 1700 oxygen and LOCOM (conservation of mass) |
| Proust | 1700 LODP (def. proportions) |
| Dalton | 1800 LOMP (multiple proportions). Atomic theory. |
| Thomson | 1900. CRT tubes. Discovered electrons. Determined electron had mass, - charge and in all matter. |
| Robert Millikan | 1904. found exact charge & mass of an electron. Electron is 1/1837 of a hydrogen atom. |
| Thomson's model | cookie dough, plum pudding. |
| Rutherford | alpha particle @ gold foil. Nucleus small, but has all mass. Most of atom = empty space. |
| Henri Becquerel | Discovered uranium. 1st to describe radioactivity. |
| Marie Curie | discovered Radium and radioactive elements. |
| Atomic # | Z (# of protons) |
| Atomic Mass # | A (protons and neutrons) |
| atomic mass unit | amu |
| p+, n*, e- | protons, neutrons, electrons |
| mole | 6.022x10^23 |
| Avogadro's # | 6.022x10^23 |
| nucleon | protons and neutrons |
| nuclide | atom; identified by # of protons and neutrons. Ex: 228:88 Ra or Radium-228. |
| Ratio of neutrons:protons in low atomic # elements | 1:1 |
| Ratio in larger atomic # elements | 1.5:1 |
| 2, 8, 20, 28, 50, 82, 126 | magic cuz stable combination in dif nuclear shells |
| Alpha particle | 2 protons and neutrons bound together (4:2 He) |
| Gamma rays released in order to | make nucleus more stable |
| Roentgen | 2*10^9 ion pairs passing through 1 cm^3 of dry air. |
| Rem | dose of type of ionizing radiation; radiation effect on human tissue. |