Chemical element chemical bonds, they form chemical compounds. Only a minority of elements are found uncombined as relatively pure minerals. Among the more common of such native elements are copper, silver, gold, carbon (as coal, graphite, or diamonds), and sulfur. All but a few of the most inert elements, such as noble gases and noble metals, are usually found on Earth in chemically combined form, as chemical compounds. While about 32 of the chemical elements occur on Earth in native uncombined forms, most of these occur as mixtures. For example, atmospheric air is primarily a mixture of nitrogen, oxygen, and argon, and
Cobalt-59 nuclear magnetic resonance Cobalt-59 nuclear magnetic resonance Cobalt-59 nuclear magnetic resonance is a form of nuclear magnetic resonance spectroscopy that uses cobalt-59, a cobalt isotope. Co is a nucleus of spin 7/2 and 100% abundancy. The nucleus has a magnetic quadrupole moment. Among all NMR active nuclei, Co has the largest chemical shift range and the chemical shift can be correlated with the spectrochemical series. Resonances are observed over a range of 20000 ppm, the width of the signals being up to 20 kHz. A widely used standard is potassium hexacyanocobaltate (0.1M KCo(CN) in DO), which, due to its high symmetry, has a