| I'm fine with an ion being considered a particle. We talk about particles of sand and dust, and those are much larger than atoms. What you consider a "particle" all depends on the length scale of the phenomenon you're interested in. For example, even protons have structure to them -- they're made up of 3 quarks. If what your interested is nuclear dynamics, then you wouldn't want to consider the proton as a particle at all, but rather an entity comprising three particles: the quarks. But if what you're interested in is the flow of wheat kernels down chutes in food processing plants, then you can think of something as large as a wheat kernel as a particle. |
