Holmium is a chemical element with the symbol Ho and atomic number 67. Part of the lanthanide series, holmium is a rare earth element. Holmium was discovered by Swedish chemist Per Theodor Cleve. Its oxide was first isolated from rare earth ores in 1878 and the element was named after the city of Stockholm.Symbol: Ho
Electron configuration: Xe 4f11 6s2
Melting point: 1,474 °C
Atomic number: 67
Atomic mass: 164.93032 ± 0.00002 u
Discoverers: Marc Delafontaine, Jacques-Louis Soret, Per Teodor Cleve