Actinium

Actinium,  ₈₉Ac

Picture of a sample of actinium in a v-vial, glowing blue due to its extreme radiation ionizing the air surrounding the sample. Oak Ridge National Laboratory, Actinium sample (31481701837), Image resized, CC BY 2.0
General properties
Name, symbol	Actinium, Ac
Appearance	Silvery metallic, glows lightly blue in the dark
Actinium in the periodic table
La ↑ Ac ↓ Ubu Radium ← Actinium → Thorium
Atomic number	89
Standard atomic weight (Ar)
Element category	Actinides
Group, block	3 (sometimes considered group n/a); d-block (sometimes considered to be f-block)
Period	period 7
Electron configuration	[Rn] 6d1 7s2
per shell	2, 8, 18, 32, 18, 9, 2
Physical properties
Phase	solid
Melting point	1500 K ​(1227 °C, ​2240 °F) (estimated)
Boiling point	3500±300 K ​(3200±300 °C, ​​5800±500 °F) (extrapolated)
Density near r.t.	10 g/cm3
Heat of fusion	14 kJ/mol
Heat of	400 kJ/mol
Molar heat capacity	27.2 J/(mol·K)
Atomic properties
Oxidation states	+3
Electronegativity	Pauling scale: 1.1
energies	1st: 499 kJ/mol 2nd: 1170 kJ/mol 3rd: 1900 kJ/mol (more)
Covalent radius	215 pm
Miscellanea
Thermal conductivity	12 W/(m·K)
CAS Registry Number	7440-34-8
History
Discovery and first isolation	Friedrich Oskar Giesel (1902)
Named by	André-Louis Debierne (1899)

Actinium (Ac) is a highly radioactive, silvery-metallic element with a bluish glow due to its extreme radiation.

Properties

Chemical

To do

Physical

Actinium is a soft metal, comparable to sodium in consistency. Pure actinium is silvery-white, though it quickly oxidises in air to form a white crust. It has a density of approximately 10g/cm³. Due to it's intense radiation, actinium glows a dull blue-green.

Availability

Due to its extreme radioactivity and the difficulty to produce it, it is only available to a select few industries for very high prices.

Isolation

Even though extremely impractical, one might be able to extract very tiny amounts of it from uranium ores. It occurs in thorium, but at so small amounts that it's basically impossible to extract enough of it to be able to collect it.

Projects

• Element collection

Handling

Safety

Actinium is extremely radioactive and emits a lot of carcinogenic and toxic radiation. Handle it in a glove box with thick gloves and walls, walls preferably of lead glass.

Storage

Store in a thick lead-walled container.

Disposal

The best method of disposal is probably to leave it in an area with a lot of natural radioactive ores.