In 2009, Flick Coleman at Wellesley whipped up a brilliant little web-based tool that showed how the electronegativity and energy difference of atomic orbitals leads to changes in the resulting molecular orbitals. I've used it every year. But it runs on Flash, Flash is about to die forever (no longer supported as of Jan 2021), and I don't think Flick is going to make us an HTML5 version. (And wow I know I can't do that. Does somebody else know how to do that?)

So I recorded a short video of me using that tool before we lose access to it. Nothing fancy, nothing interactive, just basically me doing what I would have done in a lecture where I use this tool. If you also used Flick's clever Flash animation, feel free to use this instead!