The starting amount of radioactive iodine-131 was 250 g. The half-life is 8 days. When Leslie measured the amount, she measured 15.625 g of radioactive iodine. How many days have elapsed between measurements? 16 24 32 64
Physics · High School · Tue Nov 03 2020
Answered on
Given the statement:
The starting amount of radioactive iodine-131 was 250 g. The half-life is 8 days. When Leslie measured the amount, she measured 15.625 g of radioactive iodine.
Determine how many days have elapsed between measurement.
Solution:
In order to determine how many days elapsed, we simply needed to divide first 250 by 2 consecutively up until 15.625.
250/2 = 125
125/2 = 62.5
62.5/2 = 31.25
31.25/2 =15.625
It can be seen that to get 15.625, 250, must be divided 4 times by 2.
This means that we can multiply 4 by 8 in order to determine the number of days that have elapsed.
= (4)(8)
= 32 days
Final answer:
= 32 days