Why has it been difficult to study the chemistry of radon?

It is difficult to study the chemistry of radon because it is a radioactive substance having a half-life(the time period to decompose the substance half to its initial concentration) of only 3.82 days.

Radon belongs to the 18 group elements with chemical formula as Rn. In general, the elements at the bottom o periodic table are radioactive, they are very dangerous to study as they emit harmful radiations. Also, compounds of radon such as RnF₂ have not been isolated, they are still in the phase of discovery. They have only been identified by radiotracer technique and no any further properties have been determined.