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
25 g
b
100 g
c
75 g
d
50 g
c) 75 g
To determine how much of element X remains after 10 days, we need to find the number of half-lives that have passed.
Since the half-life of element X is 5 days, we divide 10 by 5 to find the number of half-lives: 10/5 = 2
With each half-life, the amount of element X is reduced by half. So after 2 half-lives, the remaining amount will be 100g * (1/2) * (1/2) = 100g * (1/4) = 25g.
Therefore, the correct answer is option a) 25g.
To determine how much of element X remains after 10 days, we need to understand the concept of half-life. The half-life is the time it takes for half of the radioactive material to decay.
Given that the half-life of element X is 5 days, we know that after 5 days, half of the original sample will remain. Therefore, after the first 5 days, the sample will have 50 grams remaining.
Now, after another 5 days (for a total of 10 days), we need to find out how much of the remaining 50 grams will decay. Again, since the half-life is 5 days, we know that after another 5 days, half of the remaining 50 grams will decay.
So, after 10 days, half of the remaining 50 grams will decay, which leaves us with 25 grams remaining.
Therefore, the answer is (a) 25 g.