For the element X, 2 isotopes exist. Atoms with an atomic mass of 10.012 amu occur in 19.91% of natural samples. Atoms with an atomic mass of 11.009 amu occur in 80.09% of natural samples. What is the atomic mass of element X? 10.51 amu
10.51 amu

1081.05 amu
1081.05 amu

10.511 amu
10.511 amu

10.81 amu

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.

An electron moved from a lower energy level to a higher energy level. what most likely happened during the transition? a random amount of light was released. a fixed amount of energy was absorbed. a fixed amount of energy was released. a random amount of light was absorbed.

Aphase change from a solid to a gas is called what