When taking a measurement with a pH meter, keep the instrument in the storage solution or water until it is needed. Rinse the pH meter with deionized water or acetone and gently pat dry. Place the meter in the sample solution, and record the measurement when the pH stabilizes or reaches the maximum value

Stage in which a star’s outer layers have started to cool and grow outward?

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.

Ascientist conducted an experiment and discovered that certain plants grow faster when given a particular amount of fertilizer. anouther scientist conducted the same experiment and got similar results. which concept does this best illustrate? a) repetition b) replication c) precision d) validity