Vitamin B12, also known as cyanocobalamin, is a water-soluble vitamin that is part of the B vitamin family. B vitamins help support adrenal function, help calm and maintain a healthy nervous system, and are necessary for key metabolic processes.
For each of the 80 stable elements, the number of the stable isotopes is given. Only 90 isotopes are expected to be perfectly stable, and an additional 163 are energetically unstable, but have never been observed to decay. Thus, 253 isotopes (nuclides) are stable by definition (including tantalum-180m, for which no decay has yet been observed).
Any isotope of iron has 26 protons, and a neutral atom has 26 electrons. If the charge is +3 then it has lost three electrons and has 23. But there is no way to know how many neutrons. The number of neutrons could be 30, 31 or 32 depending on the isotope.