Kinetic isotope effect both results are large enough to be indicative of weakening of the C-N bond in the transition state that would occur in a concerted process. Since kinetic isotope effects arise from differences in isotopic masses, the largest observable kinetic isotope effects are associated with isotopic substitutions of hydrogen with deuterium (100% increase in mass) or tritium (200% increase in mass). Kinetic isotope effects from isotopic mass ratios can be as large as 36.4 using muons. They have produced the lightest hydrogen atom, H (0.113 amu), in which an electron orbits around a positive muon (μ) "nucleus" that has a mass
Atomic vapor laser isotope separation Atomic vapor laser isotope separation Atomic vapor laser isotope separation, or AVLIS, is a method by which specially tuned lasers are used to separate isotopes of uranium using selective ionization of hyperfine transitions. As compared to gas centrifuges the AVLIS process provides high energy efficiency, high separation factors, and a low volume of radioactive waste. A similar technology, using molecules instead of atoms, is molecular laser isotope separation (MLIS). The absorption lines of and U differ slightly due to hyperfine structure; for example, the U absorption peak of 502.74 nanometers shifts to 502.73 nm in U. AVLIS uses tunable dye