An archaeologist finds some ancient jewelry made frombone. The jewelry has a carbon mass of 163 g (HINT: Assume all thecarbon is 12C and determine the number of atoms) andcareful measurements show that the remaining 14C has acurrent decay rate of 21 decays/s. Determine the age of the bone(and presumably the jewelry). Remember, the ratio of 14Cto 12C when the animal died was 1.3×10-12& the half-life of 14C is 5730 y.
age of bone =
A geologist finds an old rock and wants to determine itsage using rubidium-strontium dating. This is possible because87Rb, which has a half-life of 4.75×1010 y,undergoes β − decay and becomes87Sr. The geologist determines that the ratio of87Sr to 87Rb is 0.289. Assuming there was no87Sr in the rock when it was formed, determine the ageof the rock.
age of rock =
