if you start with 150g of co-60 and 40 g remain, how much time has passed?
co-60 has a half lie of 5 yrs
To determine the time that has passed, we need to use the concept of radioactive decay and the half-life of cobalt-60 (Co-60).
The half-life of a radioactive substance is the time it takes for half of the original amount to decay. In this case, the half-life of Co-60 is 5 years.
If we start with 150g of Co-60 and 40g remain, we can calculate how many half-lives have passed.
1. Find the fraction of Co-60 remaining: Remaining mass / Initial mass:
Fraction remaining = 40g / 150g = 0.27
2. Calculate the number of half-lives that have passed using the formula:
Number of half-lives = Log base 2 (Fraction remaining)
In this case, the logarithm base 2 can be found using the logarithmic identity:
log base 2 (x) = log base 10 (x) / log base 10 (2)
Number of half-lives = log base 10 (0.27) / log base 10 (2)
3. Calculate the time that has passed by multiplying the number of half-lives by the half-life of Co-60:
Time passed = Number of half-lives * Half-life of Co-60
You can use a scientific calculator or software to calculate the logarithm and carry out the multiplication to find the exact time that has passed.