rubidium87
Rubidium-87 (87Rb) is one of the naturally occurring isotopes of rubidium. It accounts for about 27.8% of natural rubidium, with the remainder predominantly consisting of rubidium-85. 87Rb is a long-lived radioactive isotope with a half-life of about 4.88 × 10^10 years, decaying via beta emission to 87Sr. The nuclear spin is I = 3/2, and its ground-state hyperfine transition occurs at a frequency of 6.834 GHz, a property exploited in timekeeping.
As a light alkali metal, rubidium is soft and highly reactive, and 87Rb shares these chemical traits.
In practical use, 87Rb has become important in science and technology. Rubidium atomic clocks rely on the
Historically, rubidium was named for its red spectral lines, discovered in 1861 by Bunsen and Kirchhoff. The