Name________________________ Date_________________ Bonding Lab Period________________ What is one thing that atoms in molecules do not have to teach their children? How to share with others……. Purpose: To demonstrate how to make three dimensional models of covalent bonds using gumdrops to represent atoms and toothpicks to represent bonds Background: A covalent bond forms when atoms share one or more pairs of electrons. When two nonmetals bond, these atoms share their electrons with each other instead of transferring them. Substances containing covalent bonds consist of individual particles called molecules. A molecule usually consists of two or more atoms joined in a definite ratio. One way to represent atoms and molecules is to use electron dot diagrams. In this lab you will have to use electron dot diagrams to assist you in constructing threedimensional models of the following covalent compounds or diatomic molecules. Hypothesis: Can you determine how many bonds will form as a result of an electron dot diagram? Explain. (5 points) _______________________________________________________________ _______________________________________________________________ Materials: Colored pencils- red, yellow, orange, green, purple, brown Gum Drops- 1 red, 2 yellow, 2 white, 2 orange, 3 green, 4 purple Toothpicks Procedure: 1. For each covalent compound or diatomic molecule draw its correct electron dot diagram using a pencil. 2. Then, use the gum drops and toothpicks to construct a three-dimensional model. 3. Draw what each of these three-dimensional models of covalent compounds or diatomic molecules looks like using colored pencils. Carbon: Red Oxygen: Yellow Hydrogen: Green Fluorine: Purple Nitrogen: Orange Chlorine: White Use BROWN to represent the toothpicks. For the white gum drops, simply just draw a circle with your pencil to outline the white gum drop. Each Dot Diagram and Each 3D Model is 4 points each Covalent compound or Diatomic Molecule H2 Cl2 O2 H2O Electron Dot Diagram 3 D Model NH3 CF4 CO2 N2 Conclusion questions: 1. Were you able to determine how many bonds could form as a result of an electron dot diagram? (Was your hypothesis correct?) (2 points) 2. Which examples were covalent compounds and which were diatomic molecules? How were you able to decipher that? (3 points) 3. Why were the gumdrops different colors? What did the toothpicks represent? (2 points) 4. Which examples contained single bonds, double bonds or triple bonds? (5 points)Single Bond Example (s): (2 points) Double Bond Example (s): (1 point) Triple Bond Example (s): 5. Do you think water (H2O) or carbon dioxide (CO2) has stronger bonds and why? (2 points) 6. Using your knowledge of valence electrons, explain the main reason so many different molecules are made from carbon atoms? (4 points) We did not represent any metallic bonds in this lab. Why would it be difficult to draw an electron dot diagram for metallic bonds? What makes metallic bonds so unique? (5 points) Table Salt, NaCl, is an example of an ionic bond. Draw an electron dot diagram for this (be sure to use two colors to show each atom). Would it be easy to make a 3D model of this compound? (5 points)