An archaeologist finds some ancient jewelry made from bone. the jewelry has a carbon mass of 127 g (hint: assume all the carbon is 12c and determine the number of atoms) and careful measurements show that the remaining 14c has a current decay rate of 21 decays/s. determine the age of the bone (and presumably the jewelry). remember, the ratio of 14c to 12c when the animal died was 1.3×10-12 & the half-life of 14c is 5730 y.

Tooth enamel consists mainly of the mineral calcium hydroxyapatite, ca_10(po_4)_6(oh)_2. trace elements in teeth of archaeological specimens provide anthropologist with clues about diet and diseases of ancient people. students at hamline university measured strontium in enamel from extracted wisdom teeth by atomic absorption spectroscopy. solutions with a constant total volume of 10.0 ml contained 0.726 mg of dissolved tooth enamel plus variable concentrations of added sr. added sr find the concentration of sr in the 10 ml sample solution in parts per billion = ng/ml. find the concentration of sr in tooth enamel in parts per million = mu g/g.