Some Properties of Actinium and Actinoids
Property Actinium (Ac) Actinoids (Actinides)
Atomic Number 89 89-103 (Ac to Lr)
Symbol Ac Varies (e.g., Th, U, Pu)
Electronic Configuration [Rn] 6d1 7s2 Generally [Rn] 5f1-14 6d0-1 7s2
Block d-block f-block
Period 7 7
Group 3 Varies (Mainly f-block)
Oxidation States +3 (most stable) +3 to +7 (varies by element)
Density (g/cm³) 10.07 Varies (e.g., U: 19.05, Pu: 19.86)
Melting Point (°C) 1050 Varies (e.g., Th: 1750, U: 1132)
Boiling Point (°C) 3200 Varies (e.g., Th: 4790, U: 4131)
Radioactive? Yes Yes (all actinoids are radioactive)
Occurrence Rare, Found in Uranium ores Mostly synthetic, except Th, Pa, U
Common Uses Radiation source, nuclear
Nuclear
studies
reactors, weapons, medicine, power generation
Property Actinium (Ac) Actinoids (Actinides)
Atomic Number 89 89-103 (Ac to Lr)
Symbol Ac Varies (e.g., Th, U, Pu)
Electronic Configuration [Rn] 6d1 7s2 Generally [Rn] 5f1-14 6d0-1 7s2
Block d-block f-block
Period 7 7
Group 3 Varies (Mainly f-block)
Oxidation States +3 (most stable) +3 to +7 (varies by element)
Density (g/cm³) 10.07 Varies (e.g., U: 19.05, Pu: 19.86)
Melting Point (°C) 1050 Varies (e.g., Th: 1750, U: 1132)
Boiling Point (°C) 3200 Varies (e.g., Th: 4790, U: 4131)
Radioactive? Yes Yes (all actinoids are radioactive)
Occurrence Rare, Found in Uranium ores Mostly synthetic, except Th, Pa, U
Common Uses Radiation source, nuclear
Nuclear
studies
reactors, weapons, medicine, power generation
