The CaCO3 that precipitated was filtered and oven dried. A 4.38 g sample of the CaCO3 had radioactivity of 3.2d/min. Archeologists removed pieces of charcoal from a Native American campfire, burned them in O2, and bubbled theCO2 formed into Ca(OH)2 solution(limewater). Discuss how long ago was the campfire? (t1/2 of 14C= 5730 years, and the ratio of 12C:14Cin living organisms results in a specific activity of 15.3 d/min g.