• Class: Alkalines
• Period: 7
• IUPAC group: 2
• Traditional: IIa

• Discovered in: 1898 by Curie, Curie-Sklodowska
• Origin of name: LaTin: radius, (ray)
• Historical or alternate name:

Pitchblende or uraninite, carnotite sands & uranium ores

Lustrous, Silvery soft metal. Reacts with Oxygen and water.

• Atmosphere: ~0.0 ppm
• Primitive mantle: ~0.0 ppm
• Sea water: 3e-11 ppm
• Metallic meteorite: ~0.0 ppm
• ConTinental crust: ~0.0 ppm
• Solar photosphere: ~0.0 log of abundance
• Oceanic crust: ~0.0 ppm
• Solar system: ~0.0 relative to Si=1.0e6

   Hazards

Highly radiotoxic. Carcinogen by inhalation, ingestion, or exposure..

• Lower:
• Upper:0.01

Radium Physical Properties

 Transitional Data

• State: Solid
• Density: 5.0 g/cm3

 Molar enthalpy

• Atomization: 159.0 kJ mol-1
• Fusion: 7.15 kJ mol-1
• Vaporization: 136.7 kJ mol-1

 Transition points

• MelTing point: 973.0 K
• Boiling point: 1413.0 K
• Critical temperature: 3510.0 K

 Molar properties

• Atomic weight: 226.0254 g/mole
• Molar volume: 41.337 cm3 mol-1

 Crystal structure sequence

body-centered-cubic

 Thermodynamics

• State: solid
  • Enthalpy 0
  • Gibbs function 0
  • Entropy 71
  • Heat Capacity 27.1

• State: gas
  • Enthalpy 159
  • Gibbs function 130
  • Entropy 176.47
  • Heat Capacity 20.79

 Miscellaneous physical

• Electrical resistivity: 100.0 µ-ohms/cm
• Debye temperature: K
• Thermal conductivity: 18.6 W / m / K
• Coefficient of linear expansion: Coef. per K
• Mass magnetic susceptibility:
• X-ray diffraction mass absorption coefficients:
• CuK: 304 (µ/p)/cm2 g-1
• MoK: 172 (µ/p)/cm2 g-1

Radium Chemical Properties

 Chemical basics:

• Oxidation states: +2
• Molecular wt: 226.0254 g/mole

 Radii

• Covalent: pm
• Atomic: 235.0 pm
• Van der Waals: pm

 Ions:

• ion: +2 pm 143.0

 Covalent bonds

 Effective nuclear charge

• Slater: 1.65
• Clementi:
• Froese-Fischer:

 Electronegativity

• Pauling: 0.9
• Allred-Rochow: 0.97

 Standard reactions

Radium Nuclear Properties

• Known 16
• Listed 4

• Known 213 - 230
• Listed 223 - 228

• % Occ.:Natural
• Mossbauer NRA:
• Nuclear spin/Quantum no.:
• Radioisotopes:
  • Half-life: 11.4 days
  • Decay mode: alpha,
  • Source:
• Notes

• % Occ.:Natural
• Mossbauer NRA:
• Nuclear spin/Quantum no.:
• Radioisotopes:
  • Half-life: 14.8 days
  • Decay mode: Beta-
  • Source:
• Notes

• % Occ.:Natural
• Mossbauer NRA:
• Nuclear spin/Quantum no.:
• Radioisotopes:
  • Half-life: 1622.0 years
  • Decay mode: alpha,
  • Source:
• Notes med

• % Occ.:Natural
• Mossbauer NRA:
• Nuclear spin/Quantum no.:
• Radioisotopes:
  • Half-life: 6.7 years
  • Decay mode: Beta-
  • Source:
• Notes

• Isotope 226Cross-section 20±3 barns

Radium Energy Properties

Electrons

• Ground state electron configuration: [Rn] 7s2
• Electron affinity: kJ mol-1
• Filling orbitals:

 Ionization energies

 Atomic energy levels