Mendelevium

Actinide · atomic number 101

101258MdMendeleviumSolidActinide

Mendelevium is a synthetic element with chemical symbol Md (formerly Mv) and atomic number 101. A metallic radioactive transuranic element in the actinide series, it is the first element that currently cannot be produced in macroscopic quantities through neutron bombardment of lighter elements. It is the antepenultimate actinide and the ninth transuranic element.

Properties of Mendelevium

Element category	Actinide
Atomic number	101
Atomic mass	258 u
Phase at STP	Solid
Group	3
Period	7
Block	f
Electron configuration	[Rn] 5f13 7s2
Electrons per shell	2, 8, 18, 32, 31, 8, 2
Electronegativity (Pauling)	1.3
Melting point	1100 K (827 °C)
Discovered by	Lawrence Berkeley National Laboratory

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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/Mendelevium

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