The emission spectrum of hydrogen shows discrete, bright, colored lines. Which characteristic of the Bohr model is best supported by this observation?
Energy is released when an electron moves to a higher energy level.
Smaller atoms have fewer spectral lines than larger atoms.
The energy of an electron increases with distance from the nucleus.
Electrons cannot exist in locations other than in specific orbits.

What overall charge must all compounds have

What is the mass of 4 molecules of co2

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.