Stable isotope Actinium (Ac)

Isotope Atomic Mass Half-life Mode of Decay Nuclear Spin Nuclear Magnetic Moment
Ac-224 224.021708 2.7 hours β- to Th-224; α to Fr-220; EC to Ra-224 0 No data available
Ac-225 225.02322 10.0 days α to Fr-221 3/2 No data available
Ac-226 226.026089 1.224 days β- to Th-226; α to Fr-222; EC to Ra-226 1 No data available
Ac-227 227.027750 21.77 years β- to Th-228; α to Fr-224 3/2 1.1
Ac-228 228.031104 6.15 hours β- to Th-229 3 No data available
Ac-229 229.03293 1.04 hours No data available 3/2 No data available

Properties of Actinium

Name Actinium
Symbol Ac
Atomic number 89
Atomic weight 227
Standard state Solid at 298 ºK
CAS Registry ID 7440-34-8
Group in periodic table N/A
Group name Actinoids
Period in periodic table 7 (Actinoid)
Block in periodic table f-block
Color Silvery
Classification Metallic
Melting point 1050 ºC
Boiling point 3300 °C
Vaporization point 3198 ºC
Thermal conductivity 12 (estimate) W/(m·K)
Electronegativity 1.1
Heat of vaporization 400 kJ·mol-1
Heat of fusion 14 kJ·mol-1
Density of solid 10.07 g/cm3
Electron configuration [Rn]6d17s2
Oxidation state +3