A radioactive isotope has a half-life of 2 minutes. How many total minutes will it take for 100-g of the isotope to get to just 6.25-g remaining

It would take 12 minutes.

8 minutes

Explanation:

G(g)                 T(min)

100 0

502

25 4

12.5    6

6.25 8

     another    way:

100/6.25 = 16

  16 = 2⁴       ( 4 half lives)    

Each half life is 2 minutes

so 4 half lives will be 8 minutes

the correct answer would be b. amelia, because the particals of gas move really fast (charged particals) and gas also has a lot of room (particals move independently) so the only answer that has both of those is amelia's.