Aportion of the periodic table is shown below: a portion of the fifteenth and sixteenth columns of the periodic table is shown. column 15 from reads seven nitrogen 14.007 and 15 phosphorus 30.974. column 16 reads eight oxygen 15.999 and 16 sulfur 32.065. which element has the electron configuration 1s22s22p4? nitrogen (n) oxygen (o) phosphorus (p) sulfur (s)

)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.