Ra228
Radium-228, denoted as 228Ra, is a radioactive isotope of the element radium (atomic number 88) with a mass number of 228. It is produced in the decay of thorium-232 and is a member of the thorium decay series that ultimately leads to lead-208. 228Ra has a half-life of about 5.75 years, making it a relatively long-lived radionuclide compared with many other radium isotopes.
The principal decay mode of 228Ra is beta decay to actinium-228 (228Ac). 228Ac itself has a much
Natural occurrence and production: 228Ra occurs in trace amounts in minerals containing thorium and uranium and
Hazards and safety: 228Ra is a radiological hazard if ingested, inhaled, or absorbed. It emits beta radiation
Uses: due to its moderate half-life and placement in the thorium decay chain, 228Ra is mainly of