The half-life for a 100-gram sample of radioactive element X is 5 days. How much of element X remains after 10 days have passed?
a
12.5 g
b
10o g - no change
c
25 g
d
50 g
The half-life of element X is 5 days, which means that after 5 days, half of the sample will remain. After 10 days, two half-lives have passed.
After the first half-life, 50 grams remain.
After the second half-life, another half of the remaining 50 grams will remain, which is 25 grams.
Therefore, the correct answer is:
c) 25 g