Question

How many half-lives have elapsed if 40 grams of Iodine-131 remain?

a) One-half
b) Two
c) Three
d) Four

Answer 1

The number of half-lives that have elapsed cannot be determined without knowing the initial amount of iodine-131.

Step-by-step explanation:

The number of half-lives that have elapsed can be calculated using the formula:

n = (log2(initial amount / remaining amount))

Since the remaining amount is 40 grams and the initial amount is not provided, it is not possible to calculate the exact number of half-lives.