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Do Now: Define the following words: Fusion Fission Decay Atom Take a look at your 1st Periodic Table Where did all of these elements come from? Guesses? Share with a neighbor… Neil De Gasse Tyson explains… https://www.youtube.com/watch?v=uKqvjEE0wF g Sum Up Elements are the remnants of star dust and LOTS of energy All elements (hydrogen to iron) form in star cores and after iron from star explosions Those elements come from “lighter”/ “smaller” atoms bumping into one another and FUSING into a bigger atom! Fission or Fusion When you come together you are… When you split apart you are… When the nuclei of chlorine and lithium combine they are experiencing… When the nucleus of Hydrogen is pulled apart, it is experiencing… Notation—two ways to write an atom Let’s try a few: Nucleons—particles found in the nucleus and bound together by the strong force Protons—positively charged particles that identify an atom AND contribute to the mass of the atom Neutrons—particles with NO charge that contribute to the mass of the atom Atomic Mass = # protons + # neutrons Isotopes Atoms of a given element with: same #protons but different # neutrons H H H http://education.jlab.org/glossary/isotope.html Isotopes of Carbon Radioactive Isotopes Isotopes of certain unstable elements that spontaneously emit particles and energy from the nucleus. Henri Beckerel 1896 accidentally observed radioactivity of uranium salts that were fogging photographic film. His associates were Marie and Pierre Curie. Marie Curie: born 1867, in Poland as Maria Sklodowska Lived in France 1898 discovered the elements polonium and radium. Knowledge led to development of X-Ray tech. Dealt with so much radioactive material that her desk is STILL radioactive more than 100 years later! http://www.radiochemistry.org/nuclearmedicine/pioneers/images/mariecurie. Marie Curie a Pioneer of Radioactivity Winner of 1903 Nobel Prize for Physics with Henri Becquerel and her husband, Pierre Curie. Winner of the sole 1911 Nobel Prize for Chemistry. Thursday 09/15/2016 Do Now: Where did Silicon (Si) come from? Where did Radium (Ra) come from? What pieces make up each of these elements? (You can draw a picture if you like) Atomic Structure Lab: Complete the practice/ initial questions and acquire teacher confirmation for each step. Play the atomic structure game in your group and write down each identified element in the game. Determine its atomic number, atomic mass and use your notes to figure out its # of protons, # of neutrons, and # of electrons Student Work Period: All work must be completed on your own paper. All students must complete the atomic structure diagram for every element. Please do not write on the class set of game handouts! Exit Card: Describe the structure of the atom and its parts. A drawing may be part of your explanation. Friday 09/16/2016 3 Main Types of Radioactive Decay Alpha a Beta b Gamma g Alpha Decay Emission of alpha particles a : helium nuclei two protons and two neutrons charge +2e can travel a few inches through air can be stopped by a sheet of paper, clothing. Alpha Decay Uranium Thorium Alpha Decay http://education.jlab.org/glossary/alphadecay.gif Beta Decay Beta particles b: electrons ejected from the nucleus when neutrons decay ( n -> p+ +b- ) Beta particles have the same charge and mass as "normal" electrons. Beta Decay Beta particles b: electrons ejected from the nucleus when neutrons decay n -> p+ +b- Beta particles have the same charge and mass as "normal" electrons. Can be stopped by aluminum foil or a block of wood. Beta Decay Beta Decay Thorium Protactinium Positron Emission (aka Beta plus decay) One proton becomes a neutron in an atom while releasing a positron and an electron neutrino: Mg Na + e + v Electron Capture: A protein rich element absorbs an inner- atomic electron and thereby changes a nuclear proton to a neutron. This releases the emission of an electron neutrino. Rb Kr + v Gamma Decay Gamma radiation g : electromagnetic energy that is released. Gamma rays are electromagnetic waves. They have no mass. Gamma radiation has no charge. Most Penetrating, can be stopped by 1m thick concrete or a several cm thick sheet of lead. Exit Card