4. In a chemical reaction, mass is conserved. This means that (1 Point) a) The mass of the reactants stays the same during a chemical reaction
b) The mass of the products stays the same during a chemical reaction
c) The type and number of atoms in the reactants equals the type and number of atoms in the products
d) The mass of the products is always twice the mass of the reactants.

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.