Thulium (Tm) is a chemical element with atomic number (Z) 69, group n/a, period 6, and atomic weight 168.934. The Thulium (Tm) is a lanthanide element, a bright silvery-gray luster and can be cut by a knife that has some corrosion resistance in dry air and good ductility, used to create lasers, a nuclear reactor and X-ray devices. (Refer to the Chemical Element; Periodic Table)
