Lithium has three electrons. The element has an atomic number of 3, which means it has three protons. Lithium lies in the alkali metal family of the periodic table of elements.
Lithium, because of its one electron in its outermost energy level, is highly reactive, as are all the elements within the alkali metal family. This element is therefore not found in its free form in nature. Lithium is a silvery metal that is found mainly in igneous rocks and mineral springs.
Johan August Arwedson discovered the element in 1817. Lithium is the lightest of all the metals and can float on water because it is only half as dense as water.