Is there such a thing as an antineutron or are they identical to a neutron :shrug:, lol. Anyway I suppose there is an antineutron.*I think this brings up the discussion of if there is really charge conservation. I think if you where someone like Benjamin Franklin trying to avoid electrocution by placing a small key on the string of a kite in the middle of a thunderstorm, then yes conservation would have a very profound effect on you. But, what about the subatomic world? I could say that a photon that has no charge could then be absorbed by an electron that is in orbit around the atom. I then could say that electron then became absorbed by a proton and then form a neutron. I could then smash this neutron into an antineutron, and then get a huge explosion of photonic energy. But wait, photons do not have charge... Where did the charge go?
How about this delusion. Photons have energy quanta but no charge while traveling at the speed of light.*They can be absorbed by either an electron or a positron and the resulting energized electron will remain negative and the resulting energized positron will remain positive.
There is enough negative charge in an electron to make a proton turn neutral, and there is enough positive charge in a positron to make an antiprotion turn neutral thus the combination of the electron and proton becomes a neutral neutron and the combination of the positron and the antiproton becomes a neutral antiproton.
The annihilation that you then get when you combine the antineutron/neutron nets out to zero charge. The photons emitted by the annihilaton returns the previously absorbed no-charge photons back to nature as light.