dennis@home coughed up some electrons that declared:

Seriously, no there isn't.

Seriously, yes there is.

The energy is within the chemical bonds and doesn't require any extra mass
to hold it.

It doesn't "require" any. It is *intrinsic*. That's the whole point and
relevance of E=mc2

If you seriously think it increases the mass can you tell us which
subatomic particle it creates and how?

Why would it need to create a particle?