Introduction Zinc-68 (Zn-68) is a stable, non-radioactive isotope of zinc, accounting for approximately 18.8% of naturally occurring zinc. With 30 protons and 38 neutrons, Zn-68

Carbon-13 (C-13) Stable Isotope – Introduction Carbon-13 (C-13) is a stable, non-radioactive isotope of carbon that makes up about 1.1% of all naturally occurring carbon.