silicon28

Silicon-28, denoted 28Si, is a stable isotope of the element silicon (atomic number 14) with a mass number of 28. It has a nuclear spin I = 0 and, as a stable isotope, does not undergo radioactive decay. Its atomic mass is about 27.9769 atomic mass units.

In nature, silicon comprises several isotopes, with 28Si accounting for about 92% of natural silicon. The remaining portion consists of 29Si and 30Si in smaller amounts. Because isotopes of an element share the same electron configuration, 28Si has the same chemical behavior as other silicon isotopes, but their different nuclear masses can affect physical properties such as lattice dynamics.

Isotopically enriched 28Si is produced through industrial isotopic separation methods to increase its abundance beyond natural levels. Such enrichment is valuable in research and technology because the absence of nuclear spin in 28Si reduces magnetic noise in certain experiments, making it advantageous for quantum computing hardware and high-precision metrology. Additionally, crystals enriched in 28Si exhibit slightly higher thermal conductivity than natural silicon due to reduced phonon scattering from mass disorder.

In astrophysics and cosmology, 28Si is a common product of stellar nucleosynthesis occurring during late stages of stellar evolution, including silicon burning. It is one of the most abundant silicon isotopes found in planetary materials and in the universe.

See also: silicon isotopes, silicon-29, silicon-30.