Actinium

ElementActiniumSymbolAc
Atomic Number89Molar Mass227.03 g mol-1
Electron Configuration[Rn]6d17s2Normal Statesolid metal
Density @STP10.07 g cm-3Melting Point1051oC
Boiling Point3200oCStable Isotopes169Tm
Atomic Radius188 pmIonic Radius118 (4+) pm
Electronegativity (Pauling)1.1Ionization Energy (1st)499 kJ mol-1
Ionization Energy (2nd)1170 kJ mol-1Ionization Energy (3rd)1900 kJ mol-1
Molar Heat Capacity27.2 J K-1mol-1Standard Molar Entropy56.5 J K-1mol-1
Enthalpy of Fusion14.2 kJ mol-1Enthalpy of Vapourization418 kJ mol-1
[[Back to Periodic table] [ Home - www.gordonengland.co.uk] ]