Question

You have 900,000 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

112,500 atoms

Step-by-step explanation:

If you begin with 900,000 atoms, to find the number of atoms remaining after three half-lives, we need to use the equation
`N(t)=N_0((1)/(2) )^(t)`, where
`N(t)` is the number remaining after the half-lives,
`N_0` is the initial number of atoms, and
`t` is the number of half-lives that have past. If we plug our numbers into the equation, we get 112,500 atoms remaining.