Which scientist performed the cathode ray experiment leading to the discovery of electrons

If 3 moles of a compound use 24 j of energy in a reaction, what is the a hreaction in j/mol?

Which liquid (h2o, h2o + soap, or h2o + salt) has the strongest cohesion and adhesion? (need now plz)

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.