Answer:
After 500 years = 165.5 grams
After 5000 years = 0 grams
500 years ago = 234.5g grams
Step-by-step explanation:
This radioactive compound decays at 0.0345% per year
For 200 grams of the compound it decays at a rate of 0.0345% per year
0.0345% of 200 = 345 / 100,000 * 200
= 0.069
So, for every year, 0.069 grams of this compound decays
In 500 years, ( 0.069 * 500 ) of this compound will decay
This gives 34. 5 grams
Therefore, Th amount which will remain after 500 years is;
200 - 34. 5 = 165.5 grams
After 5000 years,
200 - (0.069 * 5000) will remain
= 200 - (345)
= -145
Since the value is negative, it means that all of the compound would have decayed after 5000 years so, there will be nothing left = 0 grams
The amount of the compound 500 years ago will be;
200 + (0.069 * 500)
= 200 + (34.5)
= 234.5g grams
