Cyanocobalamin is the most common and widely produced form of the chemical compounds that have vitamin B12 activity.
For example, the hadron constituents of atomic nuclei, neutrons and protons, have charges of 0 e and +1 e respectively; the neutron is composed of two down quarks and one up quark, and the proton of two up quarks and one down quark.
The isotope 232 Th, although not fissionable with thermal neutrons, is a possible energy source because it absorbs thermal neutrons to produce long-lived 233 U, which also undergoes thermal neutron fission with a high probability. Thus the big three readily fissionable nuclei are: 235 U, 239 Pu, and 233 U. Fig. 14-2.