Boiling point liquid is the highest temperature (and pressure) it will actually boil at. See also Vapour pressure of water. The element with the lowest boiling point is helium. Both the boiling points of rhenium and tungsten exceed 5000 K at standard pressure; because it is difficult to measure extreme temperatures precisely without bias, both have been cited in the literature as having the higher boiling point. As can be seen from the above plot of the logarithm of the vapor pressure vs. the temperature for any given pure chemical compound, its normal boiling point can serve as an indication of that
Critical points of the elements (data page) Critical points of the elements (data page) David R. Lide (ed), "CRC Handbook of Chemistry and Physics, 85th Edition", online version. CRC Press. 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 J.A. Dean (ed), "Lange's Handbook of Chemistry" (15th Edition), McGraw-Hill, 1999; Section 6; Table 6.5 Critical Properties National Physical Laboratory, "Kaye and Laby Tables of Physical and Chemical Constants"; D. Ambrose, M.B. Ewing, M.L. McGlashan, Critical constants and second virial coefficients of