Element Fermium (Fm)

Atomic number 100 · actinide · Atomic mass 257 u

Atomic Mass
257.0000 u
Element Properties
Atomic Number 100
Atomic Mass 257.0000 u
Category actinide / 锕系元素
Group
Period 7
Block F
Electron Configuration [Rn] 5f¹² 7s²
Electronegativity (Pauling) 1.3
Phase at STP Solid
Density 9.7 g/cm³
Year Discovered 1952

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