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88
Ra
226.0254
Radium |
Appearance & Characteristics | Reactions |
Other Forms Radius | Conductivity | Abundance
General:
| Name: Radium | Symbol: Ra |
| Group: Alkali Earth | Atomic weight: 226.0254 |
| Density @ 293 K: 5 g/cm3 | Atomic volume: 45.20 cm3/mol |
| Group: Alkali Earth | Discovered: 1898 |
States
| State (s, l, g): solid | |
| Melting point: 973.2 K | Boiling point: 1973 K |
| Heat of fusion: ? | Heat of vaporization: ? |
Energies
| 1st ionization energy: 509.4 kJ/mole | |
| Electronegativity: 0.9 | 2nd ionization energy: 979.1 kJ/mole |
| Electron affinity: kJ/mole | 3rd ionization energy: kJ/mole |
| Specific heat: 0.12 J/gK | Heat atomization: 159 kJ/mole atoms |
Oxidation & Electrons
| Shells: 2,8,18,32,18,8,2 | Electron configuration: [Rn] 7s2 |
| Minimum oxidation number: 0 | Maximum oxidation number: 2 |
| Min. common oxidation no.: 0 | Max. common oxidation no.: 2 |
Appearance & Characteristics
| Structure: bcc: body-centered cubic | Color: white |
| Uses: neutron Source | Toxicity: |
| Hardness: mohs | Characteristics: Radioactive, luminescent |
Reactions
| Reaction with air: vigorous, => RaO2, Ra3N2 | |
| Reaction with 6 M HCl: | Reaction with 6 M HCl: |
| Reaction with 15 M HNO3: | Reaction with 6 M NaOH: |
Other Forms
| Number of isotopes: 4 | Hydride(s): |
| Oxide(s): | Chloride(s): RaCl2 |
Radius
| Ionic radius (2- ion): pm | Ionic radius (1- ion): pm |
| Atomic radius: pm | Ionic radius (1+ ion): pm |
| Ionic radius (2+ ion): 162 pm | Ionic radius (3+ ion): pm |
Conductivity
| Thermal conductivity: 18.6 J/m-sec-deg | |
| Electrical conductivity: 1/mohm-cm | Polarizability: 38.3 A^3 |
Abundance
| Source: pitchblende (U-238 decay) | |
| Rel. abund. solar system: log | Abundance earth's crust: -6 log |
| cost, pure: $/100g | cost, bulk: $/100g |
