Fermium

Actinide · atomic number 100

100257FmFermiumSolidActinide

Fermium is a synthetic element with symbol Fm and atomic number 100. It is a member of the actinide series. It is the heaviest element that can be formed by neutron bombardment of lighter elements, and hence the last element that can be prepared in macroscopic quantities, although pure fermium metal has not yet been prepared.

Properties of Fermium

Element category	Actinide
Atomic number	100
Atomic mass	257 u
Phase at STP	Solid
Group	3
Period	7
Block	f
Electron configuration	[Rn] 5f12 7s2
Electrons per shell	2, 8, 18, 32, 30, 8, 2
Electronegativity (Pauling)	1.3
Melting point	1800 K (1527 °C)
Discovered by	Lawrence Berkeley National Laboratory

← Einsteinium · Periodic table · Mendelevium → Md

About the actinide group

Mostly radioactive, heavy metals — several made only in reactors — whose fission powers nuclear energy and weapons.

Data: Periodic-Table-JSON (CC BY-SA 3.0) · stored statically on our server. https://en.wikipedia.org/wiki/Fermium

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