4C10  PVT Surfaces
            .10 PVT Surfaces
4C20  Phase Changes: Liquid-Solid
            .21 Ice Bomb with Glass Jar
            .45 Cooling by Expansion
4C30  Phase Changes: Liquid-Gas
            .15 Boiling at Reduced Pressure
            .35 Burst a Balloon
            .35 Blow Your Lid with LN
            .3x LN Teakettle
            .3x LN Cannon
            .50 Bromine Condensation
            .80 Make Liquid Oxygen
4C31  Cooling by Evaporation
            .20 Freezing by Evaporation
4C32  Dew Point and Humidity
4C33  Vapor Pressure
4C40  Sublimation
4C45  Phase Changes: Solid-Solid
            .15 Memory Wire
4C50  Critical Point