The radioactive isotope, phosphorus-32, has a half-life of 14.26 days. How much phosphorus-32 will remain after 60 days?

Please help.

2 answers

k = 0.693/t1/2
Substitute k into the below equation.

ln(No/N) = kt
No = The problem doesn't say how much to start with so start with 100 grams.
N = what you end up with after 60 days.
k from above.
t = 60 days

Starting with 100 g will give you a fraction and that x 100 will give you a percentage of the amount you start with that will remain after 60 days.
3.743