Period 2 element two make up all natural occurrence of lithium on Earth, although further isotopes have been synthesized. In ionic compounds, lithium loses an electron to become positively charged, forming the cation Li. Lithium is the first alkali metal in the periodic table, and the first metal of any kind in the periodic table. At standard temperature and pressure, lithium is a soft, silver-white, highly reactive metal. With a density of 0.564 g·cm, lithium is the lightest metal and the least dense solid element. Lithium is one of the few elements synthesized in the Big Bang, making it a primordial element. Lithium
Standard molar entropy all gases. Under identical conditions, it is greater for heavier gas. Standard molar entropy In chemistry, the standard molar entropy is the entropy content of one mole of substance under a standard state (not STP). The standard molar entropy is usually given the symbol "S"°, and has units of joules per mole kelvin (J mol K). Unlike standard enthalpies of formation, the value of "S"° is absolute. That is, an element in its standard state has a definite, nonzero value of "S" at room temperature. The entropy of a pure crystalline structure can be 0 J mol K only at