Launch: 11/3
  Grab your binder and immediately take a seat!
1.  Draw the correct Lewis symbols for the following atoms:
  i.      hydrogen
  ii.     neon
  iii.    nitrogen
  iv.     bromine
  v.      strontium
Schedule
  Monday (11/2): Covalent Bonds
  Tuesday (11/3): Covalent Bonds
  Wednesday (11/4): Covalent Bonds
  Thursday (11/5): Covalent Bonds
  Friday (11/6): Chemical Bonding Review
  Monday (11/9): Chemical Bonding Review
  Tuesday (11/10): Chemical Bonding Unit Exam!
Schedule
  We don’t have time to waste!
    Follow our 6 class rules
  If you have a question, ask!
    Ask your partner
    Ask me
What are Lewis
 structures?
    Mr. Heffner
     11/3/09
Review: Octet Rule
   Octet Rule:
     all atoms want to have 8 valence electrons



         •  •                                • • 
     like the noble gases




      Ne                                    F
•  • 

                   •  • 

                   • • 
        •  •        •                    • • 
       8=                             7=
Review: Covalent Bonding
  To get 8, two nonmetals share electrons



      • •                              • • 
      F                               F
                             • • 
• • 
• 

      • •                     •        • • 
    7=                              7=
Review: Covalent Bonding
  To get 8, two nonmetals share electrons


Covalent
                 • •  • • 
                 F F
 Bond




          • • 
          • • 
          • • 
                 • •  • • 
              8=              8=
What are Lewis structures?
  Lewis structures are…
    used to represent covalent bonds between atoms



                           •  • 
                    Ne
           •  • 

            Lewis Symbol
                           •  • •  • 
What are Lewis structures?
    Lewis structures are…
       used to represent covalent bonds between atoms



                     • •  • • 
  Covalent Bond




                     F- F
2 electrons = dash




                                      • • 
              • • 

   Lewis
 Structure
                     • •  • • 
What is a Lewis structure?
  There is a 3-step process for creating Lewis
  structures:
  1.  Draw Lewis symbol for each atom and count dots
  2.  Arrange atoms so they all have a full octet
      If more than 2 atoms, place first atom in center
  3.  Count dots and convert shared pairs to bonds
Example
            Draw the Lewis structure for Cl2
  Step 1: Draw Lewis symbol for each atom and count



         • •                             • • 
  dots




      Cl                               Cl
              • 


                                               • • 
• • 


                              • 
         • •         14 dots             • • 
Example
             Draw the Lewis structure for Cl2
  Step 2: Arrange atoms so they have a full octet



              • •  • • 
              Cl Cl
                       • • 
                                         • • 
      • • 

              • =•  8• • 
              8      =
Example
                     Draw the Lewis symbol for Cl2

  Step 3: Count dots and convert shared pairs to dashes


                     • •  • • 
  Covalent Bond




                     Cl-Cl
2 electrons = dash


                             • • 
                                             • • 
         • • 

                            • • 
                     • •  dots
                        14
Example
            Draw the Lewis structure for NH3
  Step 1: Draw Lewis symbol for each atom and count



         • • 
  dots




                    • 
                    • 
                    • 
      N HHH
• 
• 

         •           8 dots
Example
                   Draw the Lewis structure for NH3
     Step 2: Arrange atoms so they have a full octet
        If more than two atoms, place first atom in center



                    • • 
                   HN H
                       • • 
H is an exception to

                    •  • •  • 
                               H
   the octet rule




     2=                                           8=
Example
             Draw the Lewis structure for NH3
  Step 2: Arrange atoms so they have a full octet
    If more than two atoms, place first atom in center



              • • 
            H-N-H • • 
                  • • 
              • 
                     - • 
                           H             8 dots
Example
Draw the Lewis structure for HCl
Whiteboards
  Work in pairs
    Trade-off marker every question
  You have 60 seconds to draw the answer
    Show all three steps!
  Lift board only when prompted
H2
Br2
SH2
CH4
Practice Questions
  Practice Questions worksheet
Exit Slip
1.  In order to achieve a stable octet, two nonmetals
  a.    form   ionic bonds by transferring electrons.
  b.    form   ionic bonds by sharing electrons.
  c.    form   covalent bonds by sharing electrons.
  d.    form   metallic bonds by sharing electrons.
Exit Slip
2.  See whiteboard.
Exit Slip
3.  Which of the following correctly identifies the
   Lewis structure for HF?
Exit Slip
4.  Bubble in A
Then, draw the Lewis structure for HI
Exit Slip
5.  Bubble in A
Then, draw the Lewis symbol for CBr4
Homework
  Finish Lewis symbol and ions worksheet

11/3 What are Lewis structures?

  • 1.
    Launch: 11/3   Grabyour binder and immediately take a seat! 1.  Draw the correct Lewis symbols for the following atoms: i.  hydrogen ii.  neon iii.  nitrogen iv.  bromine v.  strontium
  • 2.
    Schedule   Monday (11/2):Covalent Bonds   Tuesday (11/3): Covalent Bonds   Wednesday (11/4): Covalent Bonds   Thursday (11/5): Covalent Bonds   Friday (11/6): Chemical Bonding Review   Monday (11/9): Chemical Bonding Review   Tuesday (11/10): Chemical Bonding Unit Exam!
  • 3.
    Schedule   We don’thave time to waste!   Follow our 6 class rules   If you have a question, ask!   Ask your partner   Ask me
  • 4.
    What are Lewis structures? Mr. Heffner 11/3/09
  • 5.
    Review: Octet Rule   Octet Rule:   all atoms want to have 8 valence electrons •  •  • •    like the noble gases Ne F •  •  •  •  • •  •  •  •  • •  8= 7=
  • 6.
    Review: Covalent Bonding  To get 8, two nonmetals share electrons • •  • •  F F • •  • •  •  • •  •  • •  7= 7=
  • 7.
    Review: Covalent Bonding  To get 8, two nonmetals share electrons Covalent • •  • •  F F Bond • •  • •  • •  • •  • •  8= 8=
  • 8.
    What are Lewisstructures?   Lewis structures are…   used to represent covalent bonds between atoms •  •  Ne •  •  Lewis Symbol •  • •  • 
  • 9.
    What are Lewisstructures?   Lewis structures are…   used to represent covalent bonds between atoms • •  • •  Covalent Bond F- F 2 electrons = dash • •  • •  Lewis Structure • •  • • 
  • 10.
    What is aLewis structure?   There is a 3-step process for creating Lewis structures: 1.  Draw Lewis symbol for each atom and count dots 2.  Arrange atoms so they all have a full octet   If more than 2 atoms, place first atom in center 3.  Count dots and convert shared pairs to bonds
  • 11.
    Example Draw the Lewis structure for Cl2   Step 1: Draw Lewis symbol for each atom and count • •  • •  dots Cl Cl •  • •  • •  •  • •  14 dots • • 
  • 12.
    Example Draw the Lewis structure for Cl2   Step 2: Arrange atoms so they have a full octet • •  • •  Cl Cl • •  • •  • •  • =•  8• •  8 =
  • 13.
    Example Draw the Lewis symbol for Cl2   Step 3: Count dots and convert shared pairs to dashes • •  • •  Covalent Bond Cl-Cl 2 electrons = dash • •  • •  • •  • •  • •  dots 14
  • 14.
    Example Draw the Lewis structure for NH3   Step 1: Draw Lewis symbol for each atom and count • •  dots •  •  •  N HHH •  •  •  8 dots
  • 15.
    Example Draw the Lewis structure for NH3   Step 2: Arrange atoms so they have a full octet   If more than two atoms, place first atom in center • •  HN H • •  H is an exception to •  • •  •  H the octet rule 2= 8=
  • 16.
    Example Draw the Lewis structure for NH3   Step 2: Arrange atoms so they have a full octet   If more than two atoms, place first atom in center • •  H-N-H • •  • •  •  - •  H 8 dots
  • 17.
    Example Draw the Lewisstructure for HCl
  • 18.
    Whiteboards   Work inpairs   Trade-off marker every question   You have 60 seconds to draw the answer   Show all three steps!   Lift board only when prompted
  • 19.
  • 20.
  • 21.
  • 22.
  • 23.
  • 24.
    Exit Slip 1.  Inorder to achieve a stable octet, two nonmetals a.  form ionic bonds by transferring electrons. b.  form ionic bonds by sharing electrons. c.  form covalent bonds by sharing electrons. d.  form metallic bonds by sharing electrons.
  • 25.
  • 26.
    Exit Slip 3.  Whichof the following correctly identifies the Lewis structure for HF?
  • 27.
    Exit Slip 4.  Bubblein A Then, draw the Lewis structure for HI
  • 28.
    Exit Slip 5.  Bubblein A Then, draw the Lewis symbol for CBr4
  • 29.
    Homework   Finish Lewissymbol and ions worksheet