A researcher claims that an ancient scroll originated from Greek scholars in about 500 B.C. Its carbon-14 decay rate is 95 % of that found in living organisms. How old is the scroll? (The half-life of carbon-14 is 5730 yr) Express your answer using two significant figures. Solution first order kinetics, k = 0.693/t/12 k= 0.693/(5730) = 0.000121 y-1 k = (1/t)ln(a/x) a = living carbon ACTIVITY = 100% x = current activity = 100-95 = 5% 0.000121 = (1/t)ln(100/5) t = age of the scroll = 24758 years = 2.5*10^4years .