# Why can´t we call the energy released after the annihilation of a particle and its antiparticle pure energy? [closed]

As a particle and its antiparticle annihilate each other a huge amount of energy is released, and no mass is left. This energy always comes in the form of force mediating particles (photons, gluons). Can´t we say that this is the definition of pure energy because all the mass has disappeared? If a photon has energy, then according to the definition it is its ability to do work. But what´s the difference between the ability of a photon to to work and the ability to do work for a particle with electric charge? A photon doesn´t do work as an electron does in an electric field. The photon can´t move against a force, as the photon itself is a particle that makes up a force field. The electron cán move aginst a force thereby acquiring potential energy. The photon just disappears because in can be absorbed by the particles that produce the field.

Maybe I just want to say that a photon (or a gluon) ís energy while particles of matter possess energy.

## closed as unclear what you're asking by ACuriousMind♦, garyp, knzhou, Gert, user36790 May 26 '16 at 5:31

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• You may say that, but what's the point? The photons are still photons, they don't care whether you call them "pure energy" or not. – ACuriousMind May 25 '16 at 22:13
• Pure energy? There is lots of that in fiction, see e.g. en.wikipedia.org/wiki/Energy_being . – CuriousOne May 25 '16 at 22:25
• I don't understand this fascination that people exhibit for that phrase. In any case, the annihilation of , say a positron and an electron results in photons, and those carry both linear and angular momentum as well as energy. – dmckee May 26 '16 at 0:57
• More on pure energy: physics.stackexchange.com/q/9731/2451 , physics.stackexchange.com/q/15122/2451 and links therein. – Qmechanic May 26 '16 at 8:25