Soney listed two structures found in seedless vascular plants. 1 - stems 2 - roots which structures in nonvascular plants are similar to these two structures? a) 1 - leaves, 2 - spores b) 1 - stalks, 2 - rhizoids c) 1 - rhizoids, 2 - stalks d) 1 - spores, 2 - leaves

Your roll: experienced electron speech is adressed to: a new "freshman class" of electrons job: write a speech task: you are to pretend that you are giving a speech to a new group of electrons. be sure to mention their placement in an atom, their charge, and their role in chemical bonding (ionic and covalent) be specific!

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.

Which of the following is not an assumption that scientists must make about the natural world? a. regularity b. causality c. predictability d. plausibility