What characteristics do atoms of carbon-12,. carbon-13, and carbon-14 have in common? 1. same mass. 2. same number of protons. 3. same number of neutrons and electrons. 4. same number of neutrons and protons. 5. same number of electrons. 6. same number of protons and electrons. 7. same number of neutrons

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.