What does a particle be small or big (in relative terms). Do particles have a defined structure? I thought that it is probably because in the particle accelerators they collide, so they have a material structure. My doubt is related with the concept behind what Matter really represents. Is a electron smaller than a proton or a neutron? Is that question well proposed?. The inclusion of the wave function of this tiny particles sometimes makes think if particles, at that level, are allowed to define a concept of size.