|MadSci Network: Physics|
For the sake of others reading this thread, let me explain some of the relevant terminology. In particle physics, all elementary particles and composite particles are either bosons or fermions. The distinction depends on the total spin of the particle. Fermions are particles with half-integer spin (they are named after the Italian physicist Enrico Fermi). Bosons are particles with whole-integer spin (they are named after the Bengali Indian physicist Satyendra Nath Bose).
Quarks (which make up protons and neutrons) and leptons (such as the electron) are all fermions. Composite particles (such as protons or nuclei or atoms) can be either fermions or bosons, depending on their total spin. Composite particles containing an even number of fermions are bosons. Some examples of these are mesons, the nucleus of a carbon-12 atom, helium-4, and deuterium. Composite particles containing odd number of fermions are fermions. Some examples of these are baryons, the nucleus of a carbon-13 atom, helium-3, and tritium. In addition, a composite particle may contain any number of bosons with no effect on whether it is a boson or a fermion.
So, to make a long story short: ions can be either bosons or fermions. It depends on how many protons, neutrons, and electrons are left over. I hope this answers your question.
James R Holliday
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