Actinium (Ac) is a chemical element belonging to the category Actinide metal, with atomic number 89 and atomic mass 227.0000 u. This sheet describes its fundamental properties, periodic position and physical characteristics.
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Astronomy · Chemical element
Actinium
EL2H
Identity
Name: Actinium
Symbol: Ac
Atomic number: 89
Atomic mass: 227.0000 u
Position in the periodic table
Group: 3
Period: 7
Category: Actinide metal
Physico-chemical properties
Standard state: Solid
Melting point: Characteristic melting point
Density: Very high
Electron configuration: [Rn] 6d¹ 7s²
Scientific description
Actinium is a chemical element with symbol Ac and atomic number 89.
It belongs to the category of Actinide metal and occupies group 3 and period 7.
Its standard atomic mass is 227.0000 u.