After some learning on atomic physics, I came with the following question. Proton mass is 1.67262158 × 10E-27 kilograms, and its velocity is proportional to its energy. So then, in E=mc^2, you only plug the m, and you will always get the same value. I don't quite understand that a proton approaching to c has about 7 TeV (I got that from an LHC article). So then, according to E=mc^2, a proton (and every other particle) has the same energy independently of its velocity?