61Pm
Promethium
프로메튬 · プロメチウム
Lanthanide
Atomic number61
ElementPm — Promethium
Atomic mass145
CategoryLanthanide
Group3
Period6
Electron config[Xe] 4f5 6s2
Shells2,8,18,23,8,2
State (RT)Solid
Melting pt1042°C
Boiling pt3000°C
Discovered1945
Main usesLuminous paint, research
2 · 8 · 18 · 23 · 8 · 2
Group 3
Sc ScandiumY YttriumLa LanthanumCe CeriumPr PraseodymiumNd NeodymiumSm SamariumEu EuropiumGd GadoliniumTb TerbiumDy DysprosiumHo HolmiumEr ErbiumTm ThuliumYb YtterbiumLu LutetiumAc ActiniumTh ThoriumPa ProtactiniumU UraniumNp NeptuniumPu PlutoniumAm AmericiumCm CuriumBk BerkeliumCf CaliforniumEs EinsteiniumFm FermiumMd MendeleviumNo NobeliumLr Lawrencium