I'm not sure about part 1, you may need to google it, but part two is 11 protons, 11 electrons and 12 neutrons. You can find protons and electrons by just looking at the atomic number, and you can find neutrons by subtracting the atomic number from the atomic mass.
Answer:
Benzene will form a solution with hexane. c6h14
<span>8.13 g x 1 mol/126 g = 0.065 moles
0.065 mol/x L = 0.86 M
x = 0.075 liters = 75 mls volume of solution</span>
I'm guessing its Sublimation point of water
Hope this helps