The image represents the reaction between a certain number of molecules of N2 and H2. Two squares are shown. Inside the square on the left three units of two joint circles are shown. The molecular formula of nitrogen gas is shown on top of this square. The square on the right also has three units of two joint circles. The molecular formula for hydrogen gas is shown on top of this square If the maximum possible amount of NH3 is formed during the reaction, what is the leftover reactant? (4 points) One molecule of N2 One molecule of H2 Two molecules of N2 Two molecules of H2

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.