What is the effect when the pressure and temperature are higher than the critical point of an ...

What is the effect when the pressure and temperature are higher than the critical point of an element?
 
  a. There is a rapid boiling of the element that dissipates quickly into a gas.
  b. There is no difference between the gaseous and liquid state of that element.
  c. There is no difference between the solid and gaseous state of that element.
  d. There is a instant freezing of that element into a solid.
 e. There is a conversion of that element into a metal.

Question 2

What is the composition of Jupiter?
 
  a. mostly carbon dioxide and methane
  b. mostly methane
 c. mostly helium and carbon dioxide
  d. mostly nitrogen
 e. mostly hydrogen and helium

Question 3

Which is a characteristic of irregular satellites?
 
  a. prograde rotation
 b. orbit closely to parent planet
  c. spherical shape
 d. highly inclined orbit
 e. relatively large in size