| Symbol |
Ac |
|
| Atomic Number |
89 |
Relative Atomic Mass
12C = 12.0000 |
227.0728 (227Ac) |
Atomic Radius
pm |
188 |
First Ionisation Energy
kJ mol-1 |
499 |
| Electronegativity |
1.1 |
Density
kg m-3 |
10060 [293 K] |
Molar Volume
cm3 |
22.6 |
Thermal Conductivity
W m-1 K-1 |
12 [300 K] |
Melting Point
K |
1320 ± 50 |
Boiling Point
K |
3470 ± 300 |
| Number of Isotopes |
26 |
Ground State Electron
Configuration |
[Rn]6d17s2 |
| Term Symbol |
2D3/2 |
| Discovery |
Discovered by A. Debierne (Paris, France) in 1899 |
| Name Derived From |
Greek aktinos meaning 'ray' |
Name in Other
Languages |
 Croatian | Aktinij |
 Danish | actinium |
 Dutch | actinium |
 Finnish | aktinium |
 French | actinium |
 German | Actinium |
 Italian | attinio |
 Norwegian | actinium |
 Portuguese | actínio |
 Spanish | actinio |
 Swedish | aktinium |
| Peter van der Krogt's Element Multidict - element name translations in over 48 langauges |
