Half life is the time taken for a radioactive isotope to decay by half its original mass. In this case the half life of carbon-14 is 5.730 years. Using the formula; New mass = original mass × (1/2)^n; where n is the number of half lives (in this case n=1 ) New mass = 2 g × (1/2)^1 = 1 g Therefore; the mass of carbon-14 that remains will be 1 g
