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Actinium (Ac) properties


Atomic mass, symbol and atomic number

actinium is a natural element with the elementary symbol Ac and atomic number 89. In the periodic table it belongs to the actinoids with an atomic mass of 227.027 u. The chemical element discovered by André-Louis Debierne in 1899 is radioactive and is in a solid state of aggregation at room temperature.

Characteristics: Actinium (English Actinium)

General
Chemical element:actinium
Symbol:Ac
Atomic number:89
Group:scandium
Period:7
Block:d-block
Series:Transition metals
Appearance:silver
explorers:André-Louis Debierne
Year of discovery:1899
Atomic properties
Atomic mass:227,027 u
Atomic radius:195 pm
Covalent radius:215 pm
Van der Waals radius:???
Electron configuration:Rn 6d1 7s2
ionization:499 kJ / mol
Physical Properties
Physical state:firmly
Density:???
Crystal structure:cubic
Magnetism:unknown
molar volume:22,55 · 10-6 m3/ mol
Mohs hardness:???
Melting point:1050 ° C
Boiling point:3300 ° C
Heat of fusion:14 kJ / mol
Heat of vaporization:400 kJ / mol
Thermal conductivity:12 W
Chemical properties
electronegativity:1,1

Did you know that ...

  • Actinium is an intermediate in the decomposition of uranium?
  • the chemist André-Louis Debierne first discovered the element Actinium in uranium, a highly radioactive mineral?
  • Actinium is the first element in the group of Actinoids?