After 184.5 years, onky 0.625 grams of an original 20 gram sample of a radioactive isotope is left. Find the half life

half-life=T = 36.9 years

Explanation:

As we know that

N (t) = N (0) ⋅ 0.5 ^ (t / T)

N (0) = the number of atoms you start with=20 gram

and N (t) = the number of atoms left=0.625 grams

after a certain time=t=184.5 years

T=half life of a nuclide=?

Putting value in above equation we get

half-life=T = 36.9 years

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