A scientist discovers that a radioactive material has a half life of 1 day.
If this pattern continues, what amount of the radioactive material will remain at the beginning of day 3?
120(12)3−1=120(12)2=30mg
The amount remaining is given by
A(1/2)n where A is the original amount and n is the number of days that have elapsed
So we have
A(1/2)2 = A (1/4) .....so 1/4 th of the subtance remains at the start of the 3rd day
+961 
