David’s mom wants to calculate how much it will cost to drive from Los Angeles, CA, to San Francisco, CA. Gas costs $4. 00 a gallon, and the gas mileage of their car is 38 miles/gallon. What additional information does David’s mom need to do this calculation? the size of the gas tank the distance between the two cities the number of times that the gas tank will be filled along the way the speed limit on the highway between the two towns.

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.