The half-life for element X is 5 days. This means that after 5 days, half of the sample will decay and the remaining half will still remain.
After 5 days: 100 g / 2 = 50 g remaining
After another 5 days (total of 10 days): 50 g / 2 = 25 g remaining
Therefore, after 10 days have passed, 25 grams of element X remains.
The answer is (b) 25 g.
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
75 g
b
25 g
c
50 g
d
100 g
1 answer
1 answer