Consider the reaction below. 2N2O5(9)

>4NO2(g)+O2(9)

If the reaction is at dynamic equilibrium at 500 K, which statement applies to the given chemical system?

a

Ob

Ос

Od

The forward reaction stops at 500 K.

The forward and reverse reactions no longer occur.

The concentrations of the products and reactants do not change.

The rates of the forward and reverse reactions are unequal.

Isopropyl alcohol, (ch3)2choh, is a common solvent. determine the percent by mass of hydrogen in isopropyl alcohol. a) 6.71% h b) 13.4% h c) 25.0% h d) 53.3% h

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.

How are isotopes of the same element alike?