Question

1. A 50 gram sample of a radioisotope decays to 12.5 grams in 14.4 seconds. What is

the half-life of this isotope?

Answer 1

14.2 because basically you just divide it by 2 which would be half of it

That will work with all of those problems

So if it’s is a quarter of an isotope you’d divide by 4

Answer 2

Half life = 7.2 seconds

Step-by-step explanation:

`from \: decay \: equation \\ 2.303 log( (n.)/(nt) ) = kt \\ 2.303 log( (50)/(12.5) ) = k * 14.4 \\ k = (2.303 log( (50)/(12.5) ))/(14.4) \\ k = 0.096288 {s}^( - 1) \\ since \: half \: life = ( ln(2) )/(k) \\ half \: life = ( ln(2) )/(0.096288) \\ half \: life = 7.2 \: seconds`