Question

You have 400,000 atoms of a radioactive substance. After 3 half-lives have past, how many atoms remain? Remember that you cannot have a fraction of an atom, so round the answer to the nearest whole number.

Answer 1

Step-by-step explanation:

The number of atoms that remains after 3 half-lives given that it was originally 300000 atoms is 37500 atoms

Data obtained from the question

Original amount (N₀) = 300000 atoms

Number of half-lives (n) = 3

Amount remaining (N) =?

How to determine the amount remaining

The amount remaining after 3 half-lives can be obtained as illustrated below:

N = N₀ / 2ⁿ

N = 300000 / 2³

N = 300000 / 8

N = 37500 atoms