Structure Of An Atom

• Atoms


  Substances are made up of atoms
• Atom symbol


  Each type of atom is represented by a symbol on the Periodic Table
• Nucleus


  Located at the centre of an atom, made up of protons and neutrons
• Protons


  Have a positive (+) charge and a mass of 1
• Neutrons


  Have a neutral charge and a mass of 1
• Electrons


  Found in orbit around the nucleus in an electron shell, negatively charged (-) with insignificant mass
• Electron shells


  1. 1st shell = maximum of 2 electrons

  2. 2nd shell = maximum of 8 electrons

  3. 3rd shell = maximum of 18 (note that the elements we look at will actually have a maximum of 8)
• Atomic number


  Amount of protons = amount of electrons
• Atomic mass


  Amount of neutrons = atomic mass - atomic number (rounded to a whole number)