Atoms

Atoms

1. ·

   • Important People
     • John Dalton
       • Solid Sphere model
       • Said that all matter is made of atoms but they are too small to see
     • Democritus
       • Greek Philosipher
       • 1st to describe what would become atoms
       • Called it "atomos" He believed it was the smallest indivisable piece of matter (false)
     • JJ Thompson
       • discovered the electron
       • Predicted the proton
       • Plum pudding model
     • Rutherford
       • Gold Foil Experiment
         • Shot positivly charged particles at a thin sheet of gold foil and noticed that sometimes the particles were deflected at an angel, sometimes deflected straight back, and sometimes they went straight through the foil. He found that most of an atom is empty space.
       • Discovered the nucleus and confirmed protons
     • Chadwick
       • Discovered neutrons
     • Bohr
       • Concluded electrons orbited the nucleus like planets
       • Bohr Model
         • Had energy levels or "rings"
           • 1st level/ring holds a max of 2 electrons
             • 2nd level holds a max of 8
               • 3rd level holds 18
                 • 4th level holds 32
           • Each level must be filled completly before moving onto the next level *
             • *there are exeptions
           • Valence electrons
             • Electrons in the outermost energy level of an atom
               • No atom can have more than 8 valence electron (octet rule). Most atoms want to have exactly 8.
             • Lewis Dot Diagrams show the number of valence electrons an atom has

2. What makes up an atom

   • Electrons
     • Electron configuration
       • Electrons are found in orbitals within energy levels
         • An orbital is a region in an atom where there is a high probibility of finding an atom
         • Orbitals are 3D ( they have an x,y, and z orbital
         • 4 types of orbitals
           • S orbital
             • Sphere shaped
             • Surrounds the nucleus
             • 1 possible orbit
             • Holds 2 electrons
           • P orbital
             • Dumbell shaped
             • 3 possible orbitals
             • Holds a total of 6 electrons (2 in each)
           • D orbital
             • More complicated shape
             • 5 possible orbitals
             • Holds a total of 10 electrons
           • F orbital
             • Even more complex shape
             • 7 possible orbitals
             • Holds a total of 14 electrons
     • - charged
   • Nucleus
     • Protons
       • Up quark
       • Down quark
       • Up quark
       • + charged
     • Neurons
       • Down quark
       • Down quark
       • Up quark
       • 0 charged

3. Atoms on the Periodic Table

   • Atomic Mass
     • Number of protons + neutrons
   • Atomic Number
     • Number of protons
   • Neutrons
     • Atomic mass - atomic number
   • Electrons
     • = atomic number

4. Ions

   • An atom with a charge because it has lost or gained electrons
   • Cations
     • Make an atom positivly charged
     • Occur when an atoms loses electron(s)
   • Anion
     • Make an atom negatively charged
     • occur when an atom gains an electron
   • If an atom has...
     • 3 or less valence it will lose electrons
     • 4 valence it could do either
     • 5 or more valence it will gain electrons