189Os

189Os is an isotope of osmium, a chemical element. Osmium (symbol Os) is a hard, brittle, bluish-white metal that belongs to the platinum group. Its atomic number is 76, meaning it has 76 protons in its nucleus. Isotopes are variants of a chemical element that have the same number of protons but different numbers of neutrons.

The mass number of an isotope indicates the total number of protons and neutrons in its nucleus. Therefore, 189Os has 76 protons and 189 - 76 = 113 neutrons. 189Os is a stable isotope, meaning it does not undergo radioactive decay. In contrast, other isotopes of osmium, such as 185Os or 193Os, are radioactive.

Stable isotopes like 189Os can be used as tracers in scientific research, particularly in geochemistry and cosmochemistry. By analyzing the relative abundance of different isotopes in natural samples, scientists can gain insights into geological processes, the age of rocks, and the history of the solar system. 189Os is one of seven naturally occurring isotopes of osmium, along with 184Os, 186Os, 187Os, 188Os, 190Os, and 192Os. The abundance of 189Os in natural osmium is relatively low compared to some of the other stable isotopes, such as 192Os and 188Os.