What is the main difference between sleet and hail? A. Sleet starts frozen then melts as it falls. Hail starts as rain and then freezes as it falls. B. There is no difference. C. Sleet freezes as it is falling down. Hail freezes, is swept up by wind, and refrozen several times before it falls. D. Sleet freezes when it hits the ground. Hail starts as snow and then turns to ice.

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.

Imagine a small synthetic vesicle made from pure phospholipids enclosing an interior lumen containing 1 mm glucose and 1 mm sodium chloride. if the vesicle is placed in pure water, which of the following happens faster? a. na+ diffuses out. b. cl– diffuses out. c. h2o diffuses in. d. glucose diffuses out. e. sodium chloride diffuses out.

Which substance—wood or silver—is the better thermal conductor? a thermal conductor is a material that requires very little heat energy to change its temperature. explain your answer.