Compared to the atomic radius of a carbon atom, the atomic radius of a silicon atom is larger because of an increase in:
A the number of principal energy levels
B the number of neutrons
C the number of valence electrons
D the nuclear charge

Iknow the answer to 13 is b and 14 is d. i just need to know why the correct answers are correct

)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.

What is the most common reason for matter changing its state?