Ac

kemisk tegn for aktinium - actinium.

Atomic number 89

Atomic mass 227 g.mol ^-1

Electronegativity according to Pauling 1.1

Density 10.07 g.cm³ at 20°C

Melting point 1050 °C

Boiling point 3250 °C

Vanderwaals radius unknown

Ionic radius unknown

Isotopes 4

Electronic shell [ Rn ] 6d¹ 7s²

Energy of first ionization 664.6 kJ.mol ^-1

Energy of second ionization 1165.5 kJ.mol ^-1

Discovered by André Debierne in 1899

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