Answer:
The answer is 125 grams.
Explanation:
Elements and substances decay in time and the amount of time for it to be half of it's initial amount is defined as "half-life of that substance".
In the example, the initial weight is 500 grams and we are asked to determine the amount after two half-lives, which after the first half-life is 500/2 = 250 grams and after the second one, 250/2 = 125 grams remains from the parent element.
I hope this answer helps.
