On Thu, Apr 25, 2013 at 12:07 AM, <[email protected]> wrote: > In reply to Jones Beene's message of Wed, 24 Apr 2013 19:07:24 -0700: > Hi, > [snip] >>Actually The neutron has mass slightly larger than that of a proton: >>939.565378 MeV compared to 938.272046 MeV. Consequently, a deuteron has >>slightly more mass than a diproton. >> >>That is one of the many reasons why the reaction on the Sun, the one that >>results in a deuteron is extraordinarily rare. It is basically endothermic. >> > > The mass of two protons is 2.014552933 amu. > The mass of a deuteron is 2.01355362 amu. > > Note that the deuteron is actually lighter than the two protons. IOW this > reaction is exothermic. > It is this mass difference that is responsible for deuterium being bound. > > Bound nucleons weigh less than free particles, and the amount by which they > weigh less varies with the nucleus they are in. > > Regards, > > Robin van Spaandonk > > http://rvanspaa.freehostia.com/project.html >
My argument that a diproton is more massive than a deuteron was based on adding mass from doing work to overcome electrostatic repulsion. I forgot that the strong force reduces the mass of the particles, but on balance the mass of a diproton should still be greater than a deuteron. Do you agree? Harry
