Note: You are currently viewing documentation for Moodle 3.7. Up-to-date documentation for the latest stable version of Moodle may be available here: Electron pushing / curved question type.

Electron pushing / curved question type

From MoodleDocs


Curved Arrow / Electron Pushing question can be used to test and strengthen students knowledge of reaction mechanism, resonance and curved arrow notation. The instructor builds a reaction scheme/mechanism with all electron pushing arrows and the student must provide the correct arrows on the reaction during assessment. Note: This plugin requires MArvin Applets from Chemaxon

You can ask questions such as;

  • Please add curved arrows showing the flow of electrons for the following reaction?
  • Please add curved arrows showing how the following resonance structure could be obtained?


  • Interactive - students draw curved arrows representing flow of electrons.
  • Students can view step by step arrow placement.
  • Multistep reactions OK!
  • Radical or Polar reactions possible.
  • Teacher can hide or show products for varying difficulty.
  • Teacher can require strict arrow addition order.


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 nor Carl LeBlond are affiliated with Chemaxon.


This plugin requires Marvin Applets from Chemaxon which can be downloaded from 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)

A video available here, outlines using this plugin.