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• Neil DeGrasse Tyson: 'We are connected to each other, biologically to the Earth, chemically to the rest of the universe atomically.'
• Elements

  Substance where its atoms have the same number of protons in it
• Compounds


  Combination of two or more elements
• Atom


  The smallest particle of an element that can exist and still have the properties of the element
• Dalton's Atomic Theory


  • Each element is made up of tiny particles called atoms
  • The atoms of a given element are identical
  • Chemical reactions involve reorganization of the atoms—changes in the way they are bound together
  • The atoms themselves are not changed in a chemical reaction
• J.J Thomson


  • Discovered the electron in his cathode ray tube
• E. Rutherford


  • Radon and some elements emit streams of positively charged particles (alpha particles)
  • Gold Foil Experiment (may nucleid sa gold)
• Atomic radius increases as you move down a group


  More electrons in more Principal Energy Levels
• Ionization Energy


  Energy is needed to remove an electron from an atom
• Electronegativity


  Ability of an atom to attract electrons toward itself in a chemical bond