Meaning: A treeless grassy plain. Classified under: Nouns denoting spatial position. Hypernyms (prairie is a kind of...): grassland (land where grass or grasslike vegetation grows and is the dominant form of plant life). Instance hyponyms:
In thermodynamics, the triple point of a substance is the temperature and pressure at which the three phases (gas, liquid, and solid) of that substance coexist in thermodynamic equilibrium. For example, the triple point of mercury occurs at a temperature of â38.83440 Â°C and a pressure of 0.2 m Pa.
Phase Diagram of a Pure Substance. Notice the triple point of the substance. At temperatures and pressures below those of the triple point, a phase change between the solid and gas phases can take place. For some substances, such as carbon and arsenic, sublimation is much easier than evaporation.