Radioactivity

• Alpha rays


  • Positive charge, cannot penetrate paper, smoke detectors
• Beta rays


  Negative charged, stopped by aluminum, carbon dating
• Neutron


  Proton + Electron
• Gamma rays


  Neutrol, High energy, stopped by thick slab of lead, dangerous, kills cancer
• Uses of radioactivity


  • Kill cancer cells (Cobalt-60)
• Radioactivity


  The spontaneous breaking up of unstable nuclei with the emission of one or more types of radiation
• Geiger Muller Counter


  Measures radioactivity
• Transmutation


  Changing of one element into another
• Nuclear Reactions


  A process that alters the composition, structure and energy of an atomic nucleus
• Half-life


  Time taken for half of the nuclei in any given sample to decay
• Radioisotope


  A radioactive isotope of an element, consisting of atoms with unstable nuclei, which decay, emitting one or more types of radiation
• Uses of radioactivity


  Medical, food irradiation, smoke alarms, carbon dating
• Henri Becquerel: 'Discovered that uranium salts emitted penetrating ability that could affect photographic paper even when wrapped in black paper'
• Marie and Pierre Curie: 'Isolated polonium and radium, discovered radioactivity was not affected by physical and chemical testing, and that radiation came from the atom itself'
• Ernest Rutherford


  Classified radiation into 3 types according to penetrating power
• Chemical vs Nuclear


  Chemical: no new element, no nuclear radiation, chemical bonds broken + formed

  Nuclear: new element, nuclear radiation, nuclear bonds broken + formed
• Isotope: atoms of the same element with the same atomic number but different atomic mass number.