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
Greatest and least elements greatest elements is a special completeness property of a partial order. Further introductory information is found in the article on order theory. Greatest and least elements In mathematics, especially in order theory, the greatest element of a subset "S" of a partially ordered set (poset) is an element of "S" that is greater than every other element of "S". The term least element is defined dually, that is, it is an element of "S" that is smaller than every other element of "S". Formally, given a partially ordered set ("P", ≤), an element "g" of a subset "S" of "P"