I've been thinking about this for a while, my personal example was a nuclear explosion, but I'm talking in general about events in which matter is converted to energy.. Sticking to my original string of thought, in a nuclear detonation, matter is transformed into energy. But matter consists of particles that do or do not possess electrical charge. And I thought of the Charge Conservation Law. How could matter be transformed into energy, making charge... well.. disappear..? I think I might have an answer to my own question, but it's always good to be sure. I thought that maybe those particles have to be transformed in pairs, each consisting of two particles of opposite and equal of absolute value charges.. That is if a particle with X charge is converted into energy, then a particle of -X charge must also be converted.