An isotope has a half-life of 56 days. It now has 10,000 DPM/ml. What is the activity in the diluted specimen?
Very confused, any help would be appreciated!
See this.
http://www.jiskha.com/display.cgi?id=1429576498
Yes, that problem makes sense to me that you attached. How do I go about this problem though if I don't have a dilution factor? I only have the half life and the activity.
To determine the activity in the diluted specimen, we need to understand the concept of half-life and how it relates to the decay of isotopes.
The half-life of an isotope refers to the time it takes for half of the radioactive material to decay or become stable. In this case, the isotope has a half-life of 56 days, which means that every 56 days, the amount of active material in the sample will decrease by half.
Now, let's break down the problem step by step:
1. The initial activity of the isotope is given as 10,000 DPM/ml. DPM stands for disintegrations per minute, which represents the rate of decay of the radioactive material.
2. The activity decreases by half every 56 days. Since we want to determine the activity in the diluted specimen, we need to calculate how many half-lives have passed.
3. Divide the elapsed time by the half-life to determine the number of half-lives. Let's assume the elapsed time is given or known.
4. Calculate the remaining activity by halving the initial activity for each half-life that has passed. Multiply the number of half-lives by 56 days and divide it by 56 to determine the remaining activity.
For example, if the elapsed time is 112 days (equivalent to 2 half-lives), the calculations would be as follows:
- For the first half-life, the activity is halved: 10,000 DPM/ml / 2 = 5,000 DPM/ml.
- For the second half-life, the activity is halved again: 5,000 DPM/ml / 2 = 2,500 DPM/ml.
Therefore, after 2 half-lives (or 112 days), the activity in the diluted specimen would be 2,500 DPM/ml. Adjust the calculations based on the given elapsed time to find the exact activity in the diluted specimen.