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
Standard conditions for temperature and pressure below: Technical literature can be confusing because many authors fail to explain whether they are using the ideal gas constant "R", or the specific gas constant "R". The relationship between the two constants is "R" = "R" / "m", where "m" is the molecular mass of the gas. The US Standard Atmosphere (USSA) uses 8.31432 m·Pa/(mol·K) as the value of "R". However, the USSA,1976 does recognize that this value is not consistent with the values of the Avogadro constant and the Boltzmann constant. Standard conditions for temperature and pressure Standard conditions for temperature and pressure are standard sets of conditions