Question

did I do this correctly? I am having doubts about my answer

9.) Initially 100 milligrams of a radioactive substance was present, after 4 hours the mass had decreased by 2%. If the rate of decay is proportional to the amount of the substance present at the time t, Determine the half - life of the radioactive substance. ht 2010.02 „ЧК = in 2 Alt)= Aol In6/21 = 4* In01/2) = 4k => R=-.173286795 K 5.19328% .98= in in in 1.982=-17828 € => t=.12hr =17328 - 17348

Answer 1

oll let Alt) be amount of sadivactive material at timet da - KA dt kt A (t) = Ao el = A Coo (since decouse 21 ) A(4) o 98 x100 - - Ao at Time 4 mass = 100~2298 98 100 Aly) = love A(4 98=100 ek (4) 0.98 = e4k enco.98) = 4K enco.98) 4 oo5 oso 67 6829 find t such Alt =50 okt 50- loo e ekt 2 en (1/₂) = kt en2 = en (0.98) t प t 137.238 ho half-life- This is correct - answer. yours is Wrong Pou 00000