A substance has a half-life of 10,000 years and an initial mass of 1,000 grams. How many years will pass before only 250 grams of the substance's parent material is left?
1000...500....250 Isn't that two half years?
After 10 000 yrs, 1 000 / 2 = 500 grams of the substance's parent material is left.
After next 10 000 yrs, 500 / 2 = 250 grams of the substance's parent material is left.
10 000 yrs + 10 000 yrs = 20 000 yrs
I agree with Bosnian, I misread the half-life as 1000 years. Yes, two half lives is 20,000 years.
To find out how many years will pass before only 250 grams of the substance's parent material is left, we can use the concept of half-life.
The half-life of a substance is the time it takes for half of the parent material to decay or transform into another substance. In this case, the half-life is given as 10,000 years.
Initially, we have 1,000 grams of the substance. After the first half-life, half of it will decay, leaving behind 500 grams. After the second half-life, half of the remaining 500 grams will decay, leaving behind 250 grams. So, in this case, we need to determine how many half-lives it takes for the initial mass of 1,000 grams to reduce to 250 grams.
Let's do the calculations:
1st half-life: 1,000 grams -> 500 grams
2nd half-life: 500 grams -> 250 grams
From the pattern, it is evident that there were 2 half-lives required to reduce the initial mass from 1,000 grams to 250 grams. Since each half-life is 10,000 years, we can multiply 10,000 years by 2 to find the total number of years:
Total years = 10,000 years/half-life * 2 half-lives = 20,000 years
Therefore, 20,000 years will pass before only 250 grams of the substance's parent material is left.