A common mineral of barium is barytes, or barium sulfate (BaSO4). Because elements in the same peri- odic group have similar chemical properties, we might expect to find some radium sulfate (RaSO4) mixed with barytes since radium is the last member of Group 2A. However, the only source of radium com- pounds in nature is in uranium minerals. Why

The answer is "Radium is a radioactive isotope produced by spontaneous decay of its atoms of uranium, which would be a radioactive element in of itself".

Explanation:

With the symbol Ra as well as the atomic mass 88, radium is a chemical element. It is the 16th element of its periodic table and also referred to as alkaline earth metals, in group 2. It is the element, which is formed by the spontaneous decay of uranium atoms, a radioactive element in itself.

the temperature of the gas, in k, not celsius.