214Po

Polonium-214 (Po-214) is a radioactive isotope of polonium with a mass number of 214 and an atomic number of 84. It is a short‑lived alpha emitter that appears briefly as a transient daughter in the natural uranium-238 decay chain and is produced in trace amounts in environments containing radon-222.

Nuclear properties of Po-214 include a half-life of about 164 microseconds. It decays predominantly by alpha emission to lead-210 (210Pb), releasing an alpha particle with an energy of roughly 7.69 MeV. The rapid decay means Po-214 is present only fleetingly after the preceding beta decays in the chain.

Formation and occurrence of Po-214 occur in the radon-222 decay sequence: 222Rn decays through a series of short-lived progeny, with Po-214 arising as the alpha-decaying daughter of its precursor 214Bi. Because of its extremely short half-life, Po-214 is not found as a stable reservoir in nature and is typically encountered only as part of radon progeny in air or in laboratory samples studying alpha decay.

Applications and hazards: Po-214 is used in research on alpha-decay processes and occasionally as a short-lived calibration source for alpha detectors, though its brief existence limits practical use. It is highly radiotoxic if ingested or inhaled, and exposure is a concern in environments with elevated radon levels due to the rapid production of short-lived progeny.

See also: polonium isotopes, radon decay chain, uranium-238 decay chain, alpha decay.