There are 3.29g of iodine -126 remaining in a smple originally containing 26.3 g of Iodine - 126 the half life of Iodine - 126 is 13 days. How old is the sample?

At study hall test is after lunch and cant figure out htese 2 on my review packet

1 answer

WEll, follow the formula...

amountremaining=Original*e^(-.692t/13)

3.29/26/3= e^(-.692t/13)
take the ln of each side
-.207 = -.692t/13

solve for t in days.