Question

For the following problem use: It takes 100 years for half of the radioactive element

to decay (the true half life of 238U is 4.5 billion years): In a rock, you found 500 g of
238U and 3500 g of 234Th, how many years have passed since this rock was
formed?

Answer 1

12.375 billion years.

Step-by-step explanation:

This is with my limited understanding of the game. :)