Answer:
5 half lives
Step-by-step explanation:
Given that
Thorium - 236 contains the half-life of 10.0 minutes
And there is 250 grams
We need to find out the number of half lives that took place after 50.0 minutes
As in the question
1 half life is 10 minutes
So for 50 minutes, it would be
= 50 minutes × 1 half life ÷ 10 minutes
= 5 half lives