A Chemist has a 20-mg sample of polonium-218. He needed approximately 81.5% of it for an experiment. given that the half-life of polonium-218 is approximately 3.1 min, how many seconds will it take for the sample to decay to the desired mass

Question

anonymous · Answer

M=I(1.2)^t/n 
n = time of half-life

kohai · Answer

Hey, this is in the wrong section. You might receive quicker help if you post this into the science section.

anonymous · Answer

20x 0.815 = 16.3grams

anonymous · Answer

16.3= 20(1/2)^t/n

anonymous · Answer

16.3=20(1/2)^t/3.1
 3.1 min =186 seconds