Molybdenum-99

Main isotopes of molybdenum

Iso­tope Decay abun­dance half-life mode energy (MeV) pro­duct 92Mo 14.65% is stable with 50 neutrons 93Mo syn 4×103 y ε – 93Nb 94Mo 9.19% is stable with 52 neutrons 95Mo 15.87% is stable with 53 neutrons 96Mo 16.67% is stable with 54 neutrons 97Mo 9.58% is stable with 55 neutrons 98Mo 24.29% is stable with 56 neutrons 99Mo syn 65.94 h β− 0.436, 1.214 99mTc γ 0.74, 0.36, 0.14 – 100Mo 9.74% 7.8×1018 y β−β− 3.04 100Ru
Standard atomic weight (Ar)	95.95(1)

There are 33 known isotopes of molybdenum (₄₂Mo) ranging in atomic mass from 83 to 115, as well as four metastable nuclear isomers. Seven isotopes occur naturally, with atomic masses of 92, 94, 95, 96, 97, 98, and 100. Of these naturally occurring isotopes, six (all but ¹⁰⁰Mo) have never been observed to decay, but all are theoretically capable of radioactive decay. All unstable isotopes of molybdenum decay into isotopes of zirconium, niobium, technetium, and ruthenium.

Molybdenum-100 is the only naturally occurring isotope that is not stable. Molybdenum-100 has a half-life of approximately 1×10¹⁹ y and undergoes double beta decay into ruthenium-100. Molybdenum-98 is the most common isotope, comprising 24.14% of all molybdenum on Earth. Molybdenum isotopes with mass numbers 111 and up all have half-lives of approximately .15 µs.

Molybdenum-99 is produced commercially by intense neutron-bombardment of a highly purified uranium-235 target, followed rapidly by extraction. It is used as a parent radioisotope in technetium-99m generators to produce the even shorter-lived daughter isotope technetium-99m, which is used in many medical procedures.

...
Wikipedia