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Actinium

Source of the photo
http://periodictable.com/Elements/089/index.html
Author of the description
Gruiz Katalin
Actinium

Atomic number

89

Atomic mass

227 g.mol -1

Electronegativity

1.1

Density

10.07 g.cm-3 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

 

Actinium is a silvery radioactive metallic element. Actinium glows in the dark due to its intense radioactivity with a blue light.

Actinium was discovered in 1899 by André-Louis Debierne, a French chemist, who separated it from pitchblende. Friedrich Otto Giesel independently discovered actinium in 1902. The chemical behavior of actinium is similar to that of the rare earth lanthanum.

The word actinium comes from the Greek aktis, aktinos, meaning beam or ray.


Applications

It is about 150 times as radioactive as radium, making it valuable as a neutron source. Otherwise it has no significant industrial applications.

Actinium-225 is used in medicine to produce Bi-213 in a reusable generator or can be used alone as an agent for radio-immunotherapy.

Source of description

http://www.lenntech.com/periodic/elements/ac.htm

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