Re: [Phys-L] Energy & Bonds

[jbellina <inquirybellina@comcast.net>]

I've be trying to think of an example that would connect with students.  

Paul, how are your students with the idea that electrons are in energy levels and that takes energy to raise an electron to a higher level and that energy is released as photons when electrons go to a lower level.

If they buy that, then maybe you can use that to clarify the idea that energy is required to break bonds, ie raising electrons to higher molecular levels, and energy is released when bonds are formed as electrons more into lower molecular levels.

just a thought,

joe

On Nov 12, 2013, at 1:21 PM, Paul Lulai wrote:

> How do I reconcile this with U=kqq/r ?
> Isn't r getting smaller as they approach and bond?  Then U is getting larger.
>
> What is wrong with my model here?
>
> -----Original Message-----
> From: Phys-l [mailto:phys-l-bounces@phys-l.org] On Behalf Of Dr Keith S Taber
> Sent: Tuesday, November 12, 2013 11:56 AM
> To: Phys-L@Phys-L.org
> Subject: Re: [Phys-L] Energy & Bonds
>
> Hi Paul
>
> In your terms
>
> The products are more bound because they must be more bound and have LESS potential energy
>
> i.e. they require more energy to disrupt the bonds as there is stronger binding
>
> Best wishes
>
> Keith
>
>
> On 12/11/2013 15:01, Paul Lulai wrote:
> > Hi.
> > I am more aware of my conceptual shortcomings after the conversation about energy, reactions, and misconceptions.
> > I would appreciate clarification from the group on:
> > How do we reconcile the traditional Exothermic & Endothermic graphs of Energy vs reaction process with the fact that the products must be more bound and have greater potential energy? Typically the endo / exo graphs show (for an exothermic reaction) that the reactants have more energy than the products.
> >
> > I may have more follow up questions.
> > Thanks.
> > Paul.
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Joseph J. Bellina, Jr. Ph.D.
Emeritus Professor of Physics
Co-Director
Northern Indiana Science, Mathematics, and Engineering Collaborative
574-276-8294
inquirybellina@comcast.net