Question

The great-great-great-granddaughter of U-238?

Answer 1

The great-great-great-granddaughter of U-238?

the answer is Radon

Answer 2

$\huge \mathcal \color{royalblue} \mid\: ANSWER \: \mid$

In nuclear physics, a decay product (also known as a daughter product, daughter isotope, radio-daughter, or daughter nuclide) is the remaining nuclide left over from radioactive decay. Radioactive decay often proceeds via a sequence of steps (decay chain). For example, 238U decays to 234Th which decays to 234mPa which decays, and so on, to 206Pb (which is stable):