Chất nào dưới đây không phải là este?
A. HCOOC6H5 B. HCOOCH3 C. CH3COOH D. CH3COOCH3

What state of matter is ice a. liquid b. element c. solid d. gas

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.

Assignment directions: pick one of the following chemists and perform a bit of research on him/her. answer the following questions. alice hamilton             rosalind franklin marie curie             gertrude b. elion ada yonath             henry cavendish robert boyle             antoine lavoisier mario j. molina             svante arrhenius