Atomic Weight/Hydrogen Isotopes:
The symbols, atomic weights, and abundance of the three well-known isotopes of hydrogen are given in Table 2. 41H and 51H are also known. Therefore, since they decay in fractions of a single second, that is not extensively studied. Unless or else specified in this chapter, the word hydrogen involves deuterium, protium, and tritium. 1 will be used to refer to protium; confusion along with elemental hydrogen will be eliminated through spelling out the latter.
