Abundance of the chemical elements of the volatile elements hydrogen, helium, neon, and nitrogen, as well as carbon which has been lost as volatile hydrocarbons. The remaining elemental composition is roughly typical of the "rocky" inner planets, which formed in the thermal zone where solar heat drove volatile compounds into space. The Earth retains oxygen as the second-largest component of its mass (and largest atomic-fraction), mainly from this element being retained in silicate minerals which have a very high melting point and low vapor pressure. The mass-abundance of the nine most abundant elements in the Earth's crust is approximately: oxygen 46%, silicon 28%, aluminum 8.2%,
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