A Sample Originally Contained 1.28 G Of A Radioisotope. It Now Contains 1.12 G Of Its Daughter Isotope. How Many Half-Lives Have Passed Since The Sample Originally Formed? 3 4 8 16. Now we need to calculate what fraction of the original amount remains. A sample originally contained 1.28 g of a radioisotope.

Now we need to calculate what fraction of the original amount remains. It now contains 1.12 g of its daughter isotope. The fraction of the remaining parent isotope can be.