Plutonium decays with half life of 24000 years. If plutonium is stored for 72000 years, the fraction of it that remains is

Explanation

`T _(1//2) = 24,000` years
Duration of time `(t) =72,00` years
Number of half lifes `(n) = (t)/( T _(1//2)) = (72 000)/( 24 000) =3`
`therefore 1 g overset (1) to 1/2 g overset (2) to 1/4 g overset(3) to 1/8g`
`therefore ` Fraction of plutonium remains `= 1/8g`