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Atomic Models

Unit Plan

Atomic Models

Objectives

In this unit, students will use various modeling techniques to explore how both ionic and covalent chemical bonds are formed. Students will:

  • identify covalent bonds representing shared valence electrons.

  • construct Lewis dot structures representing bonds with shared valence electrons.

  • construct Lewis dot structures representing ionically bonded compounds.

  • identify ionically bonded compounds.

  • explore varying modeling techniques to represent bond formation.

Essential Questions

Related Unit and Lesson Plans

Related Materials & Resources

The possible inclusion of commercial websites below is not an implied endorsement of their products, which are not free, and are not required for this lesson plan.

Formative Assessment

  • View

    Multiple Choice Items:

    1. Which of the following is the correct structural formula for C3H8?

    A

    01a.PNG
    B

    01b.PNG

     

     

    C

    01c.PNG

     

     


    D

    01d.PNG

    2. Which best describes the formation of a covalent bond?

    A

    a bond formed through the sharing of inner electrons

    B

    a bond formed through the sharing of outer electrons

    C

    a bond formed through the transferring of inner electrons

    D

    a bond formed through the transferring of outer electrons

    3. Ionic bonds involve which two types of atoms?

    A

    metals and metals

    B

    nonmetals and nonmetals

    C

    nonmetals and metals

    D

    both A and B

    4. How many valence electrons are in calcium?

    A

    40

    B

    2

    C

    20

    D

    6

    5. The model below shows the structure of a methane molecule. What kind of model is this?

    05a.PNG

    www.globalwarmingart.com/images/thumb/2/21/Methane_Molecule_VdW.png/250px-Methane_Molecule_VdW.png

    A

    Lewis dot structure

    B

    Space-filling model

    C

    Ball-and-stick model

    D

    Two-dimensional model

    6. Which ball-and-stick model correctly represents CO2?

    06a.PNG

    7. How many valence electrons are needed for most atoms to have full outer shell?

    A

    4

    B

    6

    C

    8

    D

    10

    8. How many valence electrons are in the following Electron Dot Structure of oxygen?

    08a.PNG

    A

    2

    B

    6

    C

    4

    D

    0

     

     

    9. How many electrons are being shared in the ozone molecule shown here?

    09a.PNG

    A

    3

    B

    6

    C

    8

    D

    18

    Multiple Choice Answer Key:

    1. A

    2. B

    3. C

    4. B

    5. B

    6. B

    7. C

    8. B

    9. B

     

    Short-answer Items:

    10. Draw a Lewis dot structure, a ball-and-stick model, and a space-filling molecule for carbon dioxide (CO2).

     

     

     

     

     

     

     

     

     

     

     

     

    11. Draw a Lewis dot structure, a ball-and-stick model, and a space-filling molecule for diatomic iodine (I2).

     

     

     

     

     

     

     

     

     

     

    Short-answer key and Scoring Rubrics:

    10. Draw a Lewis dot structure, a ball-and-stick model, and a space-filling molecule for carbon dioxide (CO2).

    Lewis dot structure:

    10a.PNG

     

    Ball-and-stick model:

    10b.PNG

    Space-filling model:

    10c.PNG

    http://www.globalwarmingart.com/wiki/File:Carbon_Dioxide_Molecule_Formula_png

    Points

    Description

    3

    • Student correctly draws a Lewis dot structure.

    • Student correctly draws a ball-and-stick model.

    • Student correctly draws a space-filling model.

    2

    Student completes two of the following:

    • Student correctly draws a Lewis dot structure.

    • Student correctly draws a ball-and-stick model.

    • Student correctly draws a space-filling model.

    1

    Student completes one of the following:

    • Student correctly draws a Lewis dot structure.

    • Student correctly draws a ball-and-stick model.

    • Student correctly draws a space-filling model.

    0

    Student does not complete any correct drawings or does not answer the question.

    11. Draw a Lewis dot structure, a ball-and-stick model, and a space-filling molecule for diatomic chlorine (Cl2).

    Lewis dot structure:

    11key.PNG

    Ball-and-stick model:

    11key-2.PNG

    Space-filling model:

    11key-3.PNG

    http://upload.wikimedia.org/wikipedia/commons/thumb/6/6c/Nitrogen-3D-vdW.png/150px-Nitrogen-3D-vdW.png

     

    Points

    Description

    3

    • Student correctly draws a Lewis dot structure.

    • Student correctly draws a ball-and-stick model.

    • Student correctly draws a space-filling model.

    2

    Student completes two of the following:

    • Student correctly draws a Lewis dot structure.

    • Student correctly draws a ball-and-stick model.

    • Student correctly draws a space-filling model.

    1

    Student completes one of the following:

    • Student correctly draws a Lewis dot structure.

    • Student correctly draws a ball-and-stick model.

    • Student correctly draws a space-filling model.

    0

    Student does not complete any correct drawings or does not answer the question.

    Performance Assessment:

    Construct the following five compounds:

    MgCl2

    CO

    NH3

    C2H6

    C2H4

     

    Use the following color codes for gum drops and atoms:

    Hydrogen = clear or white

    Oxygen = red

    Nitrogen = yellow

    Magnesium = green

    Chlorine = blue

     

    You may use your periodic table. First, sketch the molecules on scratch paper. Then construct them using gumdrops to represent atoms and toothpicks to represent bonds.

    Place labeled note cards under your models to indicate whether the compounds are ionic or covalent (S-C-4_Performance Assessment Labels.doc).

     

     

    Performance Assessment Answer KEY and Scoring Rubric

    Construct the following five compounds:

    MgCl2

    CO

    NH3

    C2H6

    C2H4

    Use the following color codes for gum drops and atoms:

    Hydrogen = clear or white

    Oxygen = red

    Nitrogen = yellow

    Magnesium = green

    Chlorine = blue

     

    Note: This Answer key does not reflect the color code for the assignment. (S-C-4_Performance Assessment Answer KEY.docx).

    MgCl2 compound: Ionic

    pa-mgcl2.PNG

    www.cstephenmurray.com/onlinequizes/chemistry/ClassificationOfMatter/AtomsandMolecules/MgCl2.gif

     

    CO molecule: Covalent

    pa-cocovalent.PNG

    http://upload.wikimedia.org/wikipedia/commons/thumb/3/36/Dicarbon-dioxide-3D-balls.png/800px-Dicarbon-dioxide-3D-balls.png

     

     

    NH3 molecule: Covalent

    pa-nh3covalent.PNG

    http://upload.wikimedia.org/wikipedia/commons/thumb/0/05/Ammonia-3D-balls-A.png/777px-Ammonia-3D-balls-A.png

     

    C2H6 molecule: Covalent

    pa-c2h6covalent.PNG

    http://upload.wikimedia.org/wikipedia/commons/thumb/3/3c/Ethane-A-3D-balls.png/777px-Ethane-A-3D-balls.png

     

    C2H4 molecule: Covalent

    pa-c2h4covalent.PNG

    http://upload.wikimedia.org/wikipedia/commons/a/a1/Ethylene-3D-balls.png

    Performance Assessment Scoring Rubric:

    Points

    Description

    5

    The student completes all five of the requirements:

    • correctly creates MgCl2 compound and identifies it as an ionic compound.

    • correctly creates CO molecule and identifies it as a covalent molecule.

    • correctly creates NH3 molecule and identifies it as a covalent molecule.

    • correctly creates C2H6 molecule and identifies it as a covalent molecule.

    • correctly creates C2H4 molecule and identifies it as a covalent molecule.

    4

    The student completes four of the five requirements.

    3

    The student completes three of the five requirements.

    2

    The student completes two of the five requirements.

    1

    The student completes one of the five requirements.

    0

    The student demonstrates lack of understanding or does not attempt to complete the assessment.

DRAFT 11/19/2010
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