48 when an atom of the unstable isotope na-24 decays, it becomes an atom of mg-24 because the na-24 atom spontaneously releases(1) an alpha particle (3) a neutron(2) a beta particle (4) a positron

Many ionic compounds and a few highly polar covalent compounds are because they completely ionize in water to create a solution filled with charged ions that can conduct an electric current.

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.

Drag the tiles to the correct locations. each tile can be used more than once, but not all tiles will be used. one or more locations will remain empty. nitrosyl fluoride has the chemical formula nof nitrogen has five valence electrons, oxygen has six, and fluorine has seven. complete the lewis structure for this covalent compound. f n = = = . : : 0 : reset next um. all rights reserved us 2