In a jar of mixed nuts, why do Brazil nuts end up on top?
en.wikipedia.orgCould be attracted to a major radiation source (note the symbol)? "Radium is a chemical element with the symbol Ra and atomic number 88."
https://nutsdb.com/why-are-brazil-nuts-so-radioactive-the-su...
Shaking the jar sorts the small ones to the bottom. Sames reason chips in a big have dust at the bottom.
Depends on the size and shape of the particles, see https://www.nature.com/articles/429352a.pdf for a demonstration of the "reverse brazil nut effect".