We’re do the changes of state occur?

All matter can move from one state to another. It may require extreme temperatures or extreme pressures, but it can be done. Sometimes a substance doesn't want to change states. You have to use all of your tricks when that happens. To create a solid, you might have to decrease the temperature by a huge amount and then add pressure. For example, oxygen (O2) will solidify at -361.8 degrees Fahrenheit (-218.8 degrees Celsius) at standard pressure. However, it will freeze at warmer temperatures when the pressure is increased.

frequency, z, and the collision density, z, in carbon dioxide (co2), r 180 pm at 30 °c and 120 kpa