What does HO stand for in physics?
Holmium (Ho) Element Symbol: Ho. Atomic Number: 67. Atomic Mass: 164. Group # in Periodic Table: n/a. Holmium is a chemical element with symbol Ho and atomic number 67.Holmium is a chemical element; it has symbol Ho and atomic number 67. It is a rare-earth element and the eleventh member of the lanthanide series.