If you were provided a list of chemical formulas (ex: NaCl, CO2, CaCl2, SO3), using just the formula, how might you identify which are ionic and which are covalent?

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.

Calculate the ph at the equivalence point for the titration of a solution containing 150.0 mg of ethylamine (c2h5nh2) with 0.1000 m hcl solution. the volume of the solution at the equivalence point is 250.0 ml. kb forethylamine is 4.7 × 10−4 .

Amatch has about 21 milligrams of red phosphorus coating the tip. how many atoms of phosphorus is this?