Review of electrongegativity, geometry, polarity and intermolecular forces using Models 360

This page authored by Weslene Tallmadge, Gannon University, based on tutorials written by Weslene Tallmadge and Betty Jo Chitester, Gannon University.
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Summary

In this activity, students use the functionality provided in ChemEd DL Models 360 to view molecular models and make predictions. The student uses electronegativity to predict bond polarity, and then checks the prediction using the model. Molecular geometry is displayed in the model, providing the student with the information needed to predict and then check molecular polarity. Intermolecular forces are reviewed and then students predict important intermolecular forces in a set of molecules. Throughout the activity students are reminded of the effect on physical properties.

Learning Goals

The activity will help student to visualize molecular models.
The student will be able to define electronegativity and identify polar/nonpolar covalent bonds in a molecule; the student will identify small molecules as polar or nonpolar. (shapes: bent, tetrahedral, pyramidal)
The student will be able to identify intermolecular forces and the relative strength of these.
The student will predict the effect of intermolecular forces on certain physical properties.

Context for Use

This activity was developed to help nursing students enrolled in an organic, biological chemistry course to review concepts important to understanding intermolecular forces. It may be used as a homework assignment or group project. The work shoud be broken down into shorter segments and completed over a one or two week time span.
Students will need a computer with Java installed as well as an internet browser.

Description and Teaching Materials

The views of the molecular models are incorporated in the worksheet. Students should write down their answers to the questions on a copy of the worksheet. These may be turned into the instructor for grading or reviewed in class. All of the activity is available at the following link

http://moodle.chemeddl.org/course/view.php?id=78

Scroll down to #12 Weslene Tallmadge and click on the title.
To move from one page of the activity to the next, students will have to answer the last question correctly, and then move on. This question helps to ensure students are actually viewing the models of the molecules.




Teaching Notes and Tips

Students complete the answers to the activity and turn them in to the instructor for grading or review by the class. The activity may be done in short sections to ensure the student is understanding the basic concepts as he/she moves through the material. In order to move from one page to the next in the activity, the student must answer the multiple choice question at the bottom of the page correctly.

Students may need to clear the cache in Java and the browser.
In Windows: Go to the control panel. Make sure the view by option is set to large or small icons, not Category. Double click Java to bring up the Java control Panel. On the general tab, near the bottom there is a section for "Temporary Internet Files". Click Settings... Click the button near the bottom to "Delete Files". Both options for 'Applications and Applets' and 'Trace and Log Files' should be checked. Click OK.
In Mac: Go to Applications > Utilities > Java Preferences. Click the Network button near the top of the window. Near the bottom of this page there will be a button to Delete Files. Click Delete FIles. Both options for 'Applications and Applets' and 'Trace and Log Files' should be checked. Click OK. It also might be necessary to clear the cache in your web browser and/or restart your browser. The process varies depending on which browsers and versions are being used (Options, Internet Options, Preferences, etc).

Assessment

The teacher may assess student answers to questions to ensure student understanding. These may be turned in for homework or reviewed in class. The activity may be easily broken down into a set of shorter assignments.

References and Resources

The ChemEd DL Summit Resource Course (http://moodle.chemeddl.org/course/view.php?id=78) houses all of the submissions from two-year and four-year college faculty members who have designed resources using the Chem Ed DL (Chemical Educational Digital Library at http://www.chemeddl.org) for use in organic chemistry and general chemistry classrooms and laboratories.

This resource is based upon work supported by the National Science Foundation under Grants No. NSF-DUE 1044239 and NSF-DUE 0937796. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author and do not necessarily reflect the views of the National Science Foundation.