Lewis Structures

Question types ::: qtype_easyolewis
Maintained by Carl LeBlond
The Lewis structure question type allows teachers to design problems in which students must assign formal charges or add lone pair electrons/radicals to atoms in molecules. This question type requires Marvin Applets by Chemaxon.
Latest release:
17 sites
4 fans
Current versions available: 1


This software is no longer maintained and has been superseded by the OpenOChem LTI Assessment System.

With this question type the instructor draws valid Lewis structures with all lone pairs and charges for a molecule.  The student is presented with the structure stripped of lone pairs or formal charge, and they must add correct number of lone pairs/radicals or charges to any atoms..  Note:  This plugin requires Marvin Applets from Chemaxon
You can ask questions such as;
  • Add the formal charges to any atoms requiring it in the following structure?
  • Show all lone pair or radical electrons required to satisfy the charge on any atoms in the following molecule?


This plugin adopts the same license that Moodle does.  The Marvin Applets are free for academic purposes.


This plugin was developed at the Indiana University of Pennsylvania (IUP).  Neither IUP or Carl LeBlond are affiliated with Chemaxon.


This plugin requires Marvin Applets from Chemaxon which can be downloaded here.  Download the full package and install it at your web servers root directory.


Example questions are provided as a Moodle xml file in the examples folder. (coming soon)


This plugin is part of set EasyOChem.


Screenshot #0
Screenshot #1


Carl LeBlond (Lead maintainer)
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  • Anthony Borrow
    Wed, Apr 9, 2014, 9:53 AM

    Many thanks for sharing this plugin with the Moodle community.

    I was successfully able to install the plugin and it appears to function as expected. I am going to go ahead and approve this plugin.

    It is encouraged to follow Moodle's coding style as outlined in:


    Tthe code checker plugin can be quite helpful in fine tuning your code and can be found at:


    You may wish to consider using that tool to further improve your plugin. Below, are the initial results:

    question/type/easyolewis/lib.php - 1 error(s) and 0 warning(s)
    question/type/easyolewis/renderer.php - 3 error(s) and 4 warning(s)
    question/type/easyolewis/easyolewis_script.js - 68 error(s) and 0 warning(s)
    question/type/easyolewis/question.php - 1 error(s) and 0 warning(s)
    question/type/easyolewis/lang/en/qtype_easyolewis.php - 1 error(s) and 0 warning(s)
    question/type/easyolewis/backup/moodle2/backup_qtype_easyolewis_plugin.class.php - 1 error(s) and 0 warning(s)
    question/type/easyolewis/backup/moodle2/restore_qtype_easyolewis_plugin.class.php - 1 error(s) and 0 warning(s)
    question/type/easyolewis/backup/moodle1/lib.php - 1 error(s) and 0 warning(s)
    question/type/easyolewis/db/upgradelib.php - 1 error(s) and 0 warning(s)
    question/type/easyolewis/version.php - 1 error(s) and 0 warning(s)
    question/type/easyolewis/module.js - 1481 error(s) and 0 warning(s)
    question/type/easyolewis/edit_easyolewis_form.php - 1 error(s) and 0 warning(s)
    question/type/easyolewis/easyolewis_styles.css - 1 error(s) and 0 warning(s)
    question/type/easyolewis/questiontype.php - 1 error(s) and 0 warning(s)
    Total: 1563 error(s) and 4 warning(s)

    Peace - Anthony
  • Anthony Borrow
    Wed, Apr 9, 2014, 9:55 AM
    p.s. - It seems that it would be helpful to create a set of plugins that are related to the marvin app. Would you mind thinking up the name of that set and a short description?
  • Thu, Apr 17, 2014, 4:09 AM
    I'm still thinking about a name for this set. Would it be OK to include all my question types (not just Marvin based) into a set?
  • Thu, Mar 8, 2018, 1:29 PM
    Lewis structures show every particle and its situation in the structure of the molecule using its chemical Assignment Help symbol. Lines are drawn between molecules that are attached to each other (sets of dabs can be used rather than lines).
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  • Fri, Jul 10, 2020, 9:13 PM
    Hi, Is there any plans to update this plugin to version 3.8 / 3.9 / 4.0?
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