k = .693/t1/2
t1/2 should be in days.
Solve for k and substitute in the equation below.
ln(No/N) = kt
No = solve for this
N = 45.02
k from above
t = 85 days
Solve for No which will be 100%.
a) 45.02% of the sample remains after 85 days. Consider how you can use the percent of Ir-192 remaining and the number of days to calculate the mass remaining after 85 days.
3 answers
I should have mentioned that the initial mass is 1.75g
I must be missing something. If you had 1.75g initially and 45.02% remains, then you have 1.75 x 0.4502 = ? g remaining after 85 days. Isn't that right?