PERFORMANCE OBJECTIVES
      1.To construct models of molecules with single, double, and 
     triple bonds.
     2. To draw the structural formula for a molecule based on the 
     molecular model.
     3. To draw the electron dot formula corresponding to the 
     structural formula.
     4. To draw the structural and electron dot formulas for 
     unknown molecular models.
     DISCUSSION
     What is a chemical bond?  A chemical bond is defined to be the  
       attraction between two atoms in a molecule. 
     What type of bonding  give rise to the formation of  a 
       molecule?  A covalent bonding. 
     What is a  covalent bond? A  mutual sharing of valence 
       electrons.
     The periodic table provide information for the valence 
       electrons.
      
     DISCUSSION
     1. What type of bonding make-up Chloroform, CHCl3?  A single 
       bond.  A single bond shares two electrons, and each  
       connector represents an electron pair.
     2. What types of bonding make-up Formaldehyde , H2CO ? A 
       double and single bonds.  A double bond shares two pairs of 
       electrons.  A molecular model is constructed using two 
       connectors.
     3.    What  types of bonding make-up Hydrogen Cyanide, HCN? 
     A triple and  single bond.  A triple bond shares three  pairs of 
     electrons. A molecular model is constructed using  three 
     connectors to represent the triple bond.
     EQUIPMENT AND CHEMICALS
     Molecular Model Kit
     Directions for Using Molecular Models
     When constructing a model, a hole in a ball represents a 
       missing electron that is necessary to complete an octet.
     Two balls joined by one connector, the connector represents a 
       single bond. If two balls are joined by two connectors the 
       bond is double bond. If two balls  are joined by  three 
       connectors the bond is  triple bond.
     One rigid connector – single bond
     Two flexible connectors – double bond and  three flexible 
       connectors  - triple bond
     COLOR CODING ELEMENTS
     Yellow/White – Hydrogen (one hole)
     Black ball – Carbon (four holes)
     Red ball – Oxygen (two holes)
     Green ball – Chlorine (one hole)
     Orange ball – Bromine (one hole)
     Purple ball – Iodine (one hole)
     Blue ball – Nitrogen (three holes)
     If blue nitrogen ball has more than three holes, use a small peg 
       or tape to fill the additional hole(s).  All the holes in each 
       ball must have a connector for a model to be built correctly.