We solve this problem by using the equation as shown: A=Aoe^-(ln2/t)T where A is the final amount (1.00 g), Ao is the initial amount (which is our unknown ), t is the half-life (20.0 minutes) and lastly T time elapsed (1 h or 60 minutes). Plug in the values in the equation and you should get 8.00 grams.
