posted by Linn .
Particle A has a mass of 2 and a charge of -1. Particle B has a mass of 2 and a charge of +1. Are particle A and B necessarily antiparticles? Explain your answer.
I don't think so, but I'm not sure how I can explain why.
If the masses are exactly the same and the charges are opposite, A and B are antiparticles. I cannot explain why. That is the way it is.