Actinium

89
Ac
Gruppe
n/a
Periode
7
Blok
f
Protons
Electrons
Neutrons
89
89
138
General Properties
Atomnummer
89
Atommasse
[227]
Mass Number
227
Kategori
Actinider
Farve
Silver
Radioactive
Ja
From the Greek aktis, aktinos, meaning beam or ray
Krystalstruktur
Fladecentreret Kubisk
History
André-Louis Debierne, a French chemist, discovered actinium in 1899.

He separated it from pitchblende residues left by Marie and Pierre Curie after they had extracted radium.

Friedrich Oskar Giesel independently discovered actinium in 1902 as a substance being similar to lanthanum.
Elektroner i hver skal
2, 8, 18, 32, 18, 9, 2
Elektronkonfiguration
[Rn] 6d1 7s2
Ac
Actinium glows in the dark with a pale blue light
Physical Properties
Tilstandsform
Fast stof
Massefylde
10,07 g/cm3
Smeltepunkt
1323,15 K | 1050 °C | 1922 °F
Kogepunkt
3471,15 K | 3198 °C | 5788,4 °F
Smeltevarme
14 kJ/mol
Fordampningsvarme
400 kJ/mol
Varmefylde
0,12 J/g·K
Abundance in Earth's crust
n/a
Abundance in Universe
n/a
Illustration
Billede akkrediteringer: Images-of-elements
Illustration of actinium
CAS Number
7440-34-8
PubChem CID Number
n/a
Atomic Properties
Atomradius
-
Kovalent radius
215 pm
Elektronegativitet
1,1 (Paulings skala)
Ionization Potential
5,17 eV
Atomic Volume
22,54 cm3/mol
Varmeledningsevne
0,12 W/cm·K
Oxidationstrin
3
Applications
Actinium is used as an active element of radioisotope thermoelectric generators, for example in spacecraft.

The medium half-life of 227Ac makes it very convenient radioactive isotope in modeling the slow vertical mixing of oceanic waters.

225Ac is applied in medicine to produce 213Bi in a reusable generator or can be used alone as an agent for radiation therapy.
Actinium is highly radioactive
Isotoper
Stable Isotopes
-
Unstable Isotopes
206Ac, 207Ac, 208Ac, 209Ac, 210Ac, 211Ac, 212Ac, 213Ac, 214Ac, 215Ac, 216Ac, 217Ac, 218Ac, 219Ac, 220Ac, 221Ac, 222Ac, 223Ac, 224Ac, 225Ac, 226Ac, 227Ac, 228Ac, 229Ac, 230Ac, 231Ac, 232Ac, 233Ac, 234Ac, 235Ac, 236Ac