Welcome back Charlie,
If the atom has an electric charge, for example if it is ionized, then according to the laws of electricity and magnetism one can in principle bring it to a stop. Otherwise, no. But, you have to consider that there are other forces involved, for example thermal excitation, that can prevent a complete halt to all motion.
According to the standard lore the photon is its own anti-particle. That means, for example, the following reaction could take place...
photon + photon --> electron + positron.
In fact a similar reaction has been observed at the SLAC linear accelerator at Stanford.
For recommended reading... any first year college course textbook on Electricity and Magnetism would be fine. Unfortunately they are terribly expensive. There is a raft of web sites that contain good elementary explanations of E and M processes. I Googled "electricity and magnetism" and came up with a million hits.
One of the first was
http://theory.uwinnipeg.ca/mod_tech/node83.htmlThis is a nice little site with lots of elementary explanations. Try investigating yourself. Regards,
LeeH
(published on 07/01/07)