198Hg

198Hg is a stable isotope of the element mercury (Hg) with a mass number of 198. It contains 80 protons, and therefore has 118 neutrons. As an even-even nuclide, its nuclear spin is zero, and it possesses no nuclear magnetic moment.

This isotope is one of seven stable isotopes of mercury that occur naturally: 196Hg, 198Hg, 199Hg, 200Hg, 201Hg, 202Hg, and 204Hg. It contributes to the natural isotopic composition of mercury, which is used in various scientific analyses. Like the other stable isotopes, 198Hg is non-radioactive and does not undergo radioactive decay.

The natural abundance of 198Hg varies among samples and is determined by isotopic composition measured via mass spectrometry. Because of its stability and the presence of multiple mercury isotopes, 198Hg is frequently involved in studies of isotopic fractionation and in measurements of mercury in environmental, geological, and cosmochemical contexts. Researchers use the relative abundances of mercury isotopes, including 198Hg, to draw inferences about sources, processes, and histories of mercury in natural systems.

Because it has zero nuclear spin, 198Hg does not participate in hyperfine interactions, which has implications for certain spectroscopic techniques. This characteristic, combined with its stable nature, makes 198Hg a typical component in discussions of mercury isotopes and their applications in isotope ratio analyses. See also: mercury isotopes.