A group of students are asked to study how heart rate is impacted by exercise. The students take their heart rate seated. The students are then asked to jog in place for one minute and take their heart rate again. What is the dependent variable of this experiment? a. jogging in place for one minute.
b. the speed in which the students are jogging in place.
c. the number of heart beats counted.
d. the number of students participating in the experiment.

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.