Abstract
The conservation of baryon number and lepton number has not yet been explained. Here I present a new nomenclature where I redefine isospin and hypercharge. By doing so I explain baryon and lepton number conservation as an effect of the electric-magnetic duality and the U(1)×U(1) gauge symmetry of quantum electromagnetodynamics. By using this method I predict the quantum numbers of an octet of magnetic monopoles. Another surprising result is that both leptons and quarks have nonzero magnetic isospin, a new quantum number.



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