Erbium (Er) is a chemical element with atomic number 68, group n/a, period 6, and atomic weight 167.259. The Erbium (Er) is a soft, malleable, lustrous, silvery metal that is very stable in air and reacts very slowly with oxygen and water and dissolves in acids. Some Erbium is added to alloys with metals such vanadium because it lowers their hardness, making them more workable. (Refer to the Chemical Element; Periodic Table)
