Final answer:
Gamma decay of uranium-238 is a process of radioactive decay resulting in the emission of gamma radiation and an alpha particle, reducing the atomic number from 92 to 90, forming thorium-234 as the daughter nucleus, and part of a larger radioactive decay series leading to stable lead-206.
Step-by-step explanation:
The gamma decay of uranium-238 involves the unstable nucleus of uranium-238 undergoing decay to form a more stable nucleus, which is thorium-234.
This process is characterized by the emission of an alpha particle, which consists of two protons and two neutrons, thereby reducing the atomic number from 92 to 90 and the mass number from 238 to 234.
In addition, gamma radiation often accompanies the alpha decay, where gamma rays are emitted by the nucleus as it drops to a lower energy state.
Uranium-238 is part of a radioactive decay series, which includes multiple types of radioactive decay, such as alpha (α) and beta (β).
This series eventually leads to the creation of a stable nonradioactive isotope, lead-206 (Pb-206), after a total of 14 decay steps.
Uranium-238 has an important role in geochronology and astrophysics, as the study of its decay in stars provides insights about the age and formation of celestial bodies.