[djf]

Suppose we have a molecule of sodium chloride floating in space.

We can bombard it with a photon that has exactly the amount of energy needed to break the bond between the sodium atom and the chlorine atom.

So now we have an atom of sodium floating around, an atom of chlorine floating around, and no photon.

The photon is gone. It had mass and energy. It’s energy is represented by E=hf, where f is the frequency, and h is Plancks constant. It’s mass is then hf/C squared.

That mass went somewhere. It is now shared between the sodium and chlorine atoms.

[thackney]

The photon is gone. It had mass and energy.

I thought photons had no mass.

http://imagine.gsfc.nasa.gov/docs/ask_astro/answers/960731.html

My degree is in electrical engineering, specialized in power systems.