Submitted by Flick Coleman / Wellesley College on Wed, 03/11/2009 - 18:11
My Notes

Over the years I have developed a number of interactive tools that I use in my classes. This is a tool that seems appropriate for VIPEr. Comments are always appreciated, and I am always interested in developing new tools if there is something you might find useful.

This tool allows you to look at how molecular orbitals change as the difference in electronegativities of the parent atomic orbitals increases.


NOTE ADDED OCT 2014: As Flick's site at Wellesley is not available anymore I looked in his archive website ( and found the final version of this web resource, and it is linked below.  I have left the rest of the LO unchanged for archival purposes.  --Adam Johnson, Harvey Mudd College

Creative Commons License
Barbara Reisner / James Madison University
Although I haven't used it in class, this looks like it will be really helpful having students internalize what happens to energy levels as you go from same energy / same atom (covalent) to very different atoms (ionic). While I can draw pictures on the board in class, watching it change over time clarifies what happens with the electrons. We'll see if my students agree next year.
Wed, 03/11/2009 - 18:29 Permalink
Maggie Geselbracht / Reed College

In reply to by Barbara Reisner / James Madison University

This does look great!  And just in time to use in class tomorrow.

I think a great addition would be to couple this with images showing how the molecular orbital probability distributions change as one particular atomic orbital begins to dominate in the molecular orbital.   

Fri, 03/13/2009 - 02:11 Permalink
Flick Coleman / Wellesley College

In reply to by Maggie Geselbracht / Reed College


Take a look at and see if this is of interest. After reading your suggestion I tried to think of a reasonably honest way of showing it, and this seems to work.  The black circles represent the nuclei and the percent of A and B range from 50:50 to 99.5%B 0.5% A.



Fri, 03/13/2009 - 20:39 Permalink
Nancy Williams / Scripps College, Pitzer College, Claremont McKenna College

In reply to by Flick Coleman / Wellesley College

That's about two orders of magnitude better than the crappy drawings I've been putting up on the whiteboard all these years.... The addition of the sigma orbitals is fantastic (a corresponding sigma* would also be cool)!

Sun, 03/15/2009 - 22:54 Permalink
Adam Johnson / Harvey Mudd College

In reply to by Adam Bridgeman / The University of Sydney

I just stumbled on your update to this page, Adam.  I like the interactivity.
Wed, 02/10/2010 - 17:39 Permalink
Karen McFarlane Holman / Willamette University

In reply to by Nancy Williams / Scripps College, Pitzer College, Claremont McKenna College

Not only do I love the finished product, but I loved watching it evolve as I followed the thread.  Thanks for creating it and responding to all of the helpful comments from everyone!
Wed, 04/07/2010 - 04:14 Permalink
Adam Johnson / Harvey Mudd College

I am sad to see that the link is no longer live. I know that Flick was going to try to archive it somewhere somehow after he retired. We will update this for sure!

Tue, 07/08/2014 - 18:07 Permalink
W. Stephen McNeil / University of British Columbia Okanagan

Oh thank goodness. I need this for next week's class, just tried the link, and I think I screamed just a little when the link broke. Thanks much, Adam, for tracking down the archive. Phew!

Sat, 11/01/2014 - 20:18 Permalink
W. Stephen McNeil / University of British Columbia Okanagan

It's almost 2021, and Flash is about to lose support on all platforms, which means this tool won't run any more! So I recorded a short video of me using the tool the way I would in class, because that was easier than me learning HTML5 and making a new one.

Wed, 12/16/2020 - 15:33 Permalink
Kyle Broaders / Mount Holyoke College

I stumbled on Stephen's very nice video and went on a hunt for the original tool, which led me here. I was able to get it working after a bit of tinkering, so I thought I would share my method in case it might be useful to others.

1) Download the SWF file from the entry for Flick's personal website: link.

2) Run the SWF through an Adobe Flash emulator. I was surprised to learn that there are many emulators out there, but the first I tried was Ruffle, which worked perfectly. Upload the SWF to the demo page and enjoy!

Fri, 01/21/2022 - 16:53 Permalink
Gary Guillet / Furman University

Thanks for the instructions Kyle.  I would have never been able to find that, and with your post I got it running in ~1 min.  I like this for a quick visual using the incremental adjustments.  

Wed, 01/17/2024 - 09:43 Permalink