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).
A neutral isotope of iron has 26 electrons. Iron has 4 energy levels as follows:   * The first level holds 2  * The second level holds 8  * The third level holds 14 â¦  * The fourth level holds 2   So iron has 2 valence electrons.   The Bohr diagram is shown below: 3 people found this useful.