Answer:
10
Explanation:
An isotope's half-life is the amount of time it takes for half of the isotope's mass to decay.
The isotope has a half-life of 24 hours, or 1 day. 1 week is equal to 7 days, so the isotope will undergo 7 half-lives. The number of nuclei remaining after being halved 7 times is:
n = 1280 (½)⁷
n = 10
