State the parameter plotted on the x-axis of a mass spectrum, in the form of [Blank] to [Blank] ratio. Give the answer using two words only separated by a space.

Which of the following are sources of revenue for media companies? a. direct sales to producers b.advertising and subscriptions c. online purchase d. capital investments

Explain in detail of the four major scientific developments that spurred the formulation of the plate tectonics theory

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.