A scientist examines unknown substance 1. It appears to be quite soft to the touch and when he tries to grind it up and place it in water, it does not dissolve. But he does find that it dissolves in hexane! He tries heating the substance and it pretty quickly melts around 180 degrees Celsius. He tries running an electric current through it and it did not conduct electricity at all. He tries to boil the liquid once he has melted it and he finds it boils quite quickly at a low boiling point. What kind of substance is it?

Carbon-14 undergoes radioactive decay in the reaction above. determine the type of radiation emitted in this reaction and describe what is happening to the nucleus during this reaction.

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.

Why is the bottom layer of a trophic pyrimid the