59Co

59Co refers to cobalt-59, the only stable isotope of cobalt. It has 27 protons and 32 neutrons, and it constitutes essentially all naturally occurring cobalt. The nucleus has a nuclear spin of 7/2, which makes 59Co suitable for nuclear magnetic resonance studies and widely used in inorganic chemistry for probing cobalt centers.

Natural cobalt is almost entirely 59Co; no other stable isotopes occur in detectable amounts. Radioactive isotopes of cobalt can be produced artificially, with 60Co being the most notable example. 60Co is formed by neutron activation of 59Co and has a half-life of about 5.27 years. It decays by beta emission to nickel-60 and emits gamma rays at energies around 1.17 and 1.33 MeV, properties exploited in gamma radiography, sterilization, and radiotherapy.

Applications of 59Co span science and industry. In chemistry, 59Co NMR spectroscopy is used to characterize cobalt-containing compounds, catalysts, and coordination environments. In biology, cobalt is a central component of vitamin B12, making cobalt-containing chemistry relevant to biological systems. In industry, cobalt and its alloys are valued for hardness and catalytic properties, supporting uses in hard metals, superalloys, and various catalytic processes.

Elemental cobalt is a hard, silvery-gray metal with an atomic number of 27. Its standard atomic weight is about 58.93 g/mol. The stability of 59Co ensures its persistence in the environment and in biological systems, where cobalt chemistry plays a significant role in both materials science and biochemistry.