Question

An unknown substance has a half life of 3 minutes. How much of a 103 gram sample of that unknown substance will remain after 9 minutes?

Answer 1

12.9g

Step-by-step explanation:

k=0.693/3

k=0.231min-¹

N/N°=e^-kt

N/103=e^-0.231×9

N/103=e^-2.079

N/103=0.125

N=0.125×103

N=12.9g