Telescope lenetium Lutetium Dysprosium Promethium Nuclear control rodsetium Pacemakersetium Scandium Cerium Europium Aircraft enginesetium Ytterbium Automotive Lutexhaust systemsetium Yttrium Superconductorsetium Pulsed lasersetium Thulium Praseodymium X-raysetium Erbium Lanthanum Camera lenetium Holmium Neodymium Electrodesetium Magnetsetium Surgical suppliesetium Gadolinium Televisionsetium Optical glasetium Samarium Computer disksetium etium Terbium Headphonesetium Fluorescent lampsetium