At standard pressure, iodine (I₂) has a melting point of 113.7°C and a boiling point of 184.3°C. Its liquid phase has a density of 3.96 g/cm³ and its solid phase has a density of 4.93 g/cm³. Its critical temperature and pressure are 546°C and 115 atm while its triple point is at 114°C and 0.12 atm. Starting from a point at 75°C and 5.0 atm the following changes were made:

Step 1: The temperature is increased to 200°C at a constant pressure.
Step 2: The pressure is decreased to 0.500 atm at a constant temperature.
Step 3: The temperature is decreased to 115°C at a constant pressure.
Step 4: The pressure is decreased to 0.050 atm at a constant temperature.

Identify the starting phase and final phases of I₂.