Radioactive element ‘A’ decays over time to element ‘B’. Element ‘A’ has a half-life span of 5 days. If you started with 20 grams of A and 0 grams of B, how many grams of B would there be after a total of 10 days?
1) 0 grams
2) 2.5 grams
3) 5 grams
4) 7.5 grams
5) 10 grams
6) 12.5 grams
7) 15 grams
8) 17.5 grams
9) 20 grams
10) 22.5 grams
11) 25 grams
12) 27.5 grams