Explain how Hund’s rule, Aufbau principle, and Pauli exclusion principle govern the locations of electrons in an atom.

In this chemical reaction, 325 grams of barium (ba) react completely. how many moles of lithium (li) are produced?

Express the following number in scientific notation. 0.026890 =

)benzene and toluene form nearly ideal solutions. consider an equimolar solution of benzene and toluene. at 20 °c the vapour pressures of pure benzene and toluene are 9.9 kpa and 2.9 kpa, respectively. the solution is boiled by reducing the external pressure below the vapour pressure. calculate (i) the pressure when boiling begins, (ii) the composition of each component in the vapour, and (iii) the vapour pressure when only a few drops of liquid remain. assume that the rate of vaporization is low enough for the temperature to remain constant at 20 °c.