88Sr2

88Sr2 refers to the doubly ionized isotope of the element strontium with mass number 88. It represents a nucleus with 38 protons and 50 neutrons. A neutral 88Sr atom would have 38 electrons; removing two electrons yields the Sr2+ ion, which is isoelectronic with krypton.

88Sr is the most abundant strontium isotope, making up about 82.6% of natural strontium. Other stable isotopes are 84Sr, 86Sr, and 87Sr. The isotope is stable and has no known radioactive decay, contributing to the overall non-radioactive character of natural strontium. The natural isotopic composition of strontium is widely used in geochemical and archaeological studies through ratios such as 87Sr/86Sr.

As Sr2+, the ion has an electron configuration corresponding to krypton ([Kr]); it often appears in plasmas and in mass spectrometry. The doubly charged state affects its chemistry and spectral lines compared with the neutral atom or the singly ionized form. In precision metrology, the singly ionized isotope 88Sr+ is widely used for optical clocks, while Sr2+ remains relevant in ion-trapping and spectroscopic studies.

In geochemistry and geochronology, isotopic ratios of strontium, especially 87Sr/86Sr, are used to study provenance and aging of rocks and archaeological samples; 88Sr contributes to the natural isotopic mix. The combination of mass number 88 and a +2 charge helps identify this ion in spectrometric analyses.