I have a Ph.D. in chemistry and I have taught general chemistry at a large research university and at a small liberal arts college. For what it's worth I teach this explanation and know of other colleagues that do, and the explanation is not novel to this article. That said, it's probably less well known and less widely taught than it should be. It's counterintuitive to many people that the formation of strong bonds results in the production of heat!
> It's counterintuitive to many people that the formation of strong bonds results in the production of heat!
Not an expert in anything physics, but this strike me as a result that, while counterintuitive, should be obvious after a moment of thinking about it: as reaction tend to favor low energy states, a strong bond bond would mean low energy; and therefore the energy has to go somewhere.
Or, put another way: strong bonds require the input of more energy to break them apart, so it's not too surprising if they emit energy in the form of heat at the time of formation.
> it's probably less well known and less widely taught than it should be
This seems an important mechanism for science education content and instruction remaining wretched.
Consider "a 5-year old asks 'the Sun is a ball?! What color is the ball?!". Certainly some instructors teach it correctly. But the top 10-ish most used introductory astronomy textbooks have it wrong. And thus so do most first-tier astronomy graduate students. And this state has been stable for decades.
> the explanation is not novel to this article
Science education research is distinct from the underlying science research. If those colleagues didn't write it up and publish it, perhaps because they didn't see chemistry education research as their field... oh well.
The paper's existence makes it ever so slightly more likely some future content author gets it right, or is ever so slightly more embarrassed at having it wrong, and thus to revise it. Which over decades can sometimes move the needle. And being part of a research literature permits incremental collaborative correction, refinement, reference, and citation.
> It's counterintuitive to many people that the formation of strong bonds results in the production of heat!
A similar case. Some instructors do mention that attraction in bonds is almost all classical electrostatic attraction. Which makes this an intuitive extension of gravitational and electrostatic potential. But most instructors and textbooks don't. And so people struggle. Maybe a science education research paper or three might help. Or an interactive electron density model web app? (Something on my infinite todo list, using precomputed densities from GPAW:)
If it's a single step well, and the width of the well is fairly constant, then the steeper the slope is (stronger bonds are like stiffer springs) the deeper the well will be. You can extract the most energy with the deepest well.
It seems like gravity potential energy mental model works moderately well for chemical potentials (or more accurate enthalpy) at relatively low temperatures (vs bond energy) for statistically large numbers of molecules.
Granted it's been a few years since I studied chemistry, but isn't the word "combustion" defined as "exothermic reaction"? At least that's what wiki states. If a reaction doesn't create heat, we don't call it combustion.
Yes, in the same way an object on mercury takes more energy to reach orbit than the moon, an object falling to mercury releases more energy than it would falling to the moon.
What’s counter intuitive is what makes something a strong bond. Chemical bonds are more complex than simple gravity fields, further most chemistry involves both forming and breaking bonds. As such talking about specific bonds as strong or weak isn’t really an explanation so much as a corollary.
