How Does Mass Convert to Other Energy?

I read recently that when an atomic bomb explodes, we witness about an ounce of matter being converted into energy. Also, that a gallon of gasoline loses about a billionth of its mass when burned away in an engine...My question is about the specifics of the matter itself when it loses mass to energy:Do the atoms themselves "weigh" less now? Do they actually have less mass than similar atoms? Or, are individual atoms just eliminated?If the former, is there a way by which these lighter atoms regain their mass?Thanks
- David (age 32)
LaConner, WA, USA

It's the latter- different types of nuclei (for nuclear explosions) or molecules (for chemical ones) are left after the explosion.   The rest masses of the new nuclei or molecules add up to less than that of the originals. The extra energy goes elsewhere, mainly heat.

Mike W.

(published on 06/30/2015)