volatile parrâ Fr.: volatile A substance that vaporizes at relatively low temperatures (e.g. H2O, CO2, CO, CH4, NH3, and so forth). The opposite of volatile is → refractory. M.E., from M.Fr. volatile, from L. volatilis "fleeting, transitory, flying," from p.p. stem of volare "to fly," of unknown origin. Parrâ "flying," from paridan "to fly in the air," → Volans. |
volatile element bonpâr-e parrâ Fr.: élément volatile In → planetary science, any of a group of → chemical elements and → chemical compounds with relatively low → boiling points that are associated with a planet's or moon's → crust and/or → atmosphere. For example, H, He, C, N, O are underabundant (relative to the solar → photospheric values) in all types of → meteorites, including the C1 → carbonaceous chondrites. Any heating of the meteorite parent body subsequent to its formation would tend to drive the volatile elements out of the rock, whence it sublimated into → interplanetary medium. |