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).
From Wikipedia, the free encyclopedia. Argon (Ar) has 24 known isotopes, from 30 Ar to 53 Ar and 1 isomer (32m Ar), three of which are stable, 36 Ar, 38 Ar, and 40 Ar. On Earth, 40 Ar makes up 99.6% of natural argon. The longest-lived radioactive isotopes are 39 Ar with a half-life of 269 years, 42 Ar with a half-life of 32.9 years, and 37 Ar with a half-life of 35.04 days.