On a periodic table, element names are represented by:

The identities of substances are the same before and after which type of change

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.

Kelly has come up with an explanation for why her sister is sometimes in a good mood and other times in a bad mood. she speculates that it is based on the hours of sleep her sister got the previous night. this explanation for her sister's behaviors is an example of a(n)