Lithium be cut with a knife. When cut, it possesses a silvery-white color that quickly changes to gray as it oxidizes to lithium oxide. While it has one of the lowest melting points among all metals (180 °C), it has the highest melting and boiling points of the alkali metals. Lithium has a very low density (0.534 g/cm), comparable with pine wood. It is the least dense of all elements that are solids at room temperature; the next lightest solid element (potassium, at 0.862 g/cm) is more than 60% denser. Furthermore, apart from helium and hydrogen, it is less dense than
Vapor pressures of the elements (data page) Vapor pressures of the elements (data page) David R. Lide (ed), "CRC Handbook of Chemistry and Physics, 84th Edition". CRC Press. Boca Raton, Florida, 2003; Section 6, Fluid Properties; Vapor Pressure David R. Lide (ed), "CRC Handbook of Chemistry and Physics, 84th Edition", online version. CRC Press. Boca Raton, Florida, 2003; Section 4, Properties of the Elements and Inorganic Compounds; Vapor Pressure of the Metallic Elements National Physical Laboratory, "Kaye and Laby Tables of Physical and Chemical Constants"; Section 3.4.4, D. Ambrose, Vapour pressures from 0.2 to 101.325 kPa. Retrieved Jan 2006. W.E. Forsythe (ed.), "Smithsonian Physical Tables 9th ed.",