52Cr

52Cr is a stable isotope of chromium with mass number 52. It contains 24 protons and 28 neutrons. It is one of the four naturally occurring chromium isotopes, the others being 50Cr, 53Cr, and 54Cr. In nature, 52Cr accounts for about 83 to 84 percent of chromium atoms.

The nucleus of 52Cr is even-even, and it has nuclear spin I = 0. Consequently, 52Cr is non-radioactive and exhibits no decay over geological timescales.

Natural abundances (rough): 52Cr ~ 83.8%, 50Cr ~ 4.4%, 53Cr ~ 9.5%, 54Cr ~ 2.3%.

In isotopic studies, 52Cr serves as the reference isotope for chromium, used in mass spectrometric measurements of Cr isotopic ratios such as 53Cr/52Cr and 54Cr/52Cr. The 53Mn–53Cr decay system is used in geochronology; since 52Cr is stable, it helps calibrate isotopic measurements and interpret Cr isotope data in planetary materials.

Applications: chromium isotopic compositions are measured in geochemistry, cosmochemistry, and materials science. The isotope 52Cr is involved in calibration of mass spectrometry and in studies of isotopic fractionation.

See also: Chromium; Isotopes of chromium; Mn-Cr dating.