How do evaporation and condensation relate to heat

What is the percentage by mass of silicon (si) in iron aluminum silicate (fe3al2(sio4)3)?

8) a mixture of he, ne and ar has a pressure of 7.85 atm. if the ne has a mole fraction of 0.47 and 8) ar has a mole fraction of 0.23, what is the pressure of he? a) 4.2 atm b) 3.7 atm c) 5.5 atm d) 2.4 atm e) 1.8 atm

If a solution had a ph of 7 what is the solution