A radioisotope has a half-life of 2.5 hours.What percentage of a sample would be left after 12.5 hours?
To find out what percentage of the sample would be left after 12.5 hours, we need to divide the total time by the half-life.
Total time / Half-life = Number of half-lives
12.5 hours / 2.5 hours = 5 half-lives
Each half-life reduces the sample by half. So, after 5 half-lives, the sample is reduced by (1/2)^5 = 1/32.
To find the percentage left, we multiply the reduced fraction by 100: 1/32 * 100 = 3.125%.
Therefore, after 12.5 hours, approximately 3.125% of the sample would be left.