22 Jan 2011

The History of the 18-Electron Rule

In-Class Activity

Submitted by Sibrina Collins, The Charles H. Wright of Museum of African American History

This learning object focuses on fundamental concepts of organometallic chemistry. I use an article published in the Journal of Chemical Education (Jensen, W.B. "The Origin of the 18-Electron Rule," J. Chem. Educ. 2005, 82(1), 28) to provide students with fundamental knowledge on how (and why) the 18-electron rule was developed beginning with Irving Langmuir in 1921.  This activity consists of two components, namely reviewing counting electrons for various organometallic compounds and writing a summary (one paragraph) of the article.

Microsoft Office document icon 18ElectronRuleLO.doc31 KB
Learning Goals: 

Learning Goals:

There are various learning goals for this assignment, which reinforces concepts the student has learned in an earlier inorganic chemistry course.

1) The student will practice how to count electrons for organometallic compounds

2) The student will practice drawing organometallic compounds clearly demonstrating the geometry around each metal

3) The student will write a one-paragraph summary to enhance writing skills

Equipment needs: 


Evaluation Results: 

I recently gave an exam which included a multiple choice question asking who first developed the 18-electron rule. Eleven students took the exam and 9 students  answered the question correctly.

Creative Commons License: 
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