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Liquid helium is a physical state of helium at very low temperatures at standard atmospheric pressures. Liquid helium may show superfluidity . At standard pressure, the chemical element helium exists in a liquid form only at the extremely low temperature of −269 °C (−452.20 °F; 4.15 K).
2 He helium; use: 0.0829 CRC: 0.08 LNG: 0.0829 WEL: 0.083 ... Values refer to the enthalpy change in the conversion of liquid to gas at the boiling point (normal, 101 ...
This is a list of the various reported boiling points for the elements, with recommended values to be used elsewhere on Wikipedia. For broader coverage of this topic, see Boiling point . Boiling points, Master List format
Boca Raton, Florida, 2003; Section 6, Fluid Properties; Critical Constants. Also agrees with Celsius values from Section 4: Properties of the Elements and Inorganic Compounds, Melting, Boiling, Triple, and Critical Point Temperatures of the Elements Estimated accuracy for Tc and Pc is indicated by the number of digits.
2 He helium-4; Donnelly et al. 0.1249772 g/cm 3 (He-I at boiling point: 4.222 K) : 0.1461087 g/cm 3 (at lambda transition He-I/He-II: 2.1768 K, saturated vapor pressure) : 0.1451397 g/cm 3 (He-II superfluid at 0 K, saturated vapor pressure)
2 He helium; use: 0.0138 LNG: 0.0138 ... Values refer to the enthalpy change between the liquid phase and the most stable solid phase at the melting point (normal ...
The lowest pressure at which He-I and He-II can coexist is the vapor−He-I−He-II triple point at 2.1768 K (−270.9732 °C) and 5.0418 kPa (0.049759 atm), which is the "saturated vapor pressure" at that temperature (pure helium gas in thermal equilibrium over the liquid surface, in a hermetic container). [1]
The Gmelin rare earths handbook lists 1522 °C and 1550 °C as two melting points given in the literature, the most recent reference [Handbook on the chemistry and physics of rare earths, vol.12 (1989)] is given with 1529 °C.