Chemistry

Question Analysis
This question tests the student's understanding of the critical point on a phase diagram and the behavior of substances above this point.

Key Concept Explanation
The critical point is the highest temperature and pressure at which a substance can exist as a distinct liquid and gas. Above the critical point, the substance exists as a supercritical fluid, which has properties of both liquids and gases.

Step-by-step Solution
1. Identify the critical point: 600 K and 90 atm.
2. Determine the given conditions: T = 600 K, P = 100 atm.
3. Compare the conditions with the critical point. Here, the temperature equals the critical temperature (600 K) and the pressure exceeds the cri...