Radium (Ra)
Radium is the 88th element in the periodic table and has a symbol of Ra and atomic number of 88. It has an atomic weight of (226) and a mass number of 201. Radium has eighty-eight protons and one hundred thirteen neutrons in its nucleus, and eighty-eight electrons in seven shells. It is located in group two, period seven and block s of the periodic table. Radioactive metallic transuranic element, belongs to group 2 of the periodic table. Most stable isotope, Ra-226 has a half-life of 1602 years, which decays into radon. Isolated from pitchblende in 1898 Marie and Pierre Curie.
| Atomic Number | 88 |
|---|---|
| Atomic Weight | 226 |
| Mass Number | 201 |
| Group | 2 |
|---|---|
| Period | 7 |
| Block | s |
| Protons | 88 p+ |
|---|---|
| Neutrons | 113 n0 |
| Electrons | 88 e- |
Properties
| Physical Properties | |
|---|---|
| Atomic Radius | 215 pm
|
| Molar Volume | 45 cm³/mol
|
| Covalent Radius | 201 pm
|
| Metallic Radius | |
| Ionic Radius | 148 pm
|
| Crystal Radius | 162 pm
|
| Van der Waals Radius |
283 pm
|
| Density | 5 g/cm³
|
| Energy | |
| Proton Affinity | |
| Electron Affinity | 0.1 eV/particle
|
| Ionization Energy | 5.278424 eV/particle
|
| Heat of Vaporization | 113 kJ/mol
|
| Heat of Fusion | 9.6 kJ/mol
|
| Heat of Formation | 159 kJ/mol
|
| Electrons | |
| Electron Shells | 2, 8, 18, 32, 18, 8, 2 |
 | |
| Valence Electrons | 2 |
 | |
| Electron Configuration | [Rn] 7s2 |
  | |
| Oxidation States | 2 |
| Electronegativity |
0.9
|
| Electrophilicity | 0.6982685447294388 eV/particle
|
| Phases | |
| Phase | Solid |
| Gas Phase | |
| Boiling Point | |
| Melting Point | 969.15 K
|
| Critical Pressure | |
| Critical Temperature | |
| Triple Point | |
| Visual | |
Radium is a Silver. Ra has a CPK of #ffffff, Jmol of #007d00, and MOLCAS GV of #007d00. The Appearance of Element 88 is silvery white metallic. | |
| Color | Silver
|
| Appearance | silvery white metallic |
| Refractive Index | |
| Thermodynamic Properties | |
| Thermal Conductivity | |
| Thermal Expansion | |
| Molar Heat Capacity | |
| Specific Heat Capacity | |
| Heat Capacity Ratio (Adiabatic Index) | |
| Electrical Properties | |
| Type | Conductor |
| Electrical Conductivity | 1 MS/m
|
| Electrical Resistivity | 0.000001 m Ω
|
| Superconducting Point | |
| Magnetism | |
| Type | |
| Magnetic Susceptibility (Mass) | |
| Magnetic Susceptibility (Molar) | |
| Magnetic Susceptibility (Volume) | |
| Magnetic Ordering | |
| Curie Point | |
| Neel Point | |
| Structure | |
The lattice angles of Radium are π/2, π/2, π/2. | |
| Crystal Structure | Body Centered Cubic () |
| Lattice Constant | |
| Lattice Angles | π/2, π/2, π/2 |
| Mechanical Properties | |
| Hardness | |
| Bulk Modulus | |
| Shear Modulus | |
| Young Modulus | |
| Poisson Ratio | |
| Speed of Sound | |
| Classification | |
The CAS Group of Radium is IIA. The IUPAC Group of Ra is IIA. The Glawe Number of Element 88 is 13. The Mendeleev Number of Radium (Ra) is 10. The Pettifor Number of Radium is 13. The Geochemical Class of Ra is U/Th decay series. The Goldschmidt Class of Element 88 is litophile. | |
| Category | Alkaline earth metals, Alkaline earth metals |
| CAS Group | IIA |
| IUPAC Group | IIA |
| Glawe Number | 13 |
| Mendeleev Number | 10 |
| Pettifor Number | 13 |
| Geochemical Class | U/Th decay series |
| Goldschmidt Class | litophile |
| Other | |
The Dipole Polarizability of Radium is 246 plus or minus 4 a₀. The Allotropes of Ra is . The Neutron Cross Section of Element 88 is 13. The Quantum Numbers of Radium (Ra) is 1S0. The Space Group of Radium is 229 (Im_3m). | |
| Gas Basicity | |
| Dipole Polarizability | |
| C6 Dispersion Coefficient | |
| Allotropes | |
| Neutron Cross Section | 13
|
| Neutron Mass Absorption | |
| Quantum Numbers | 1S0 |
| Space Group | 229 (Im_3m) |
Isotopes of Radium
| Stable Isotopes | 0 |
|---|---|
| Unstable Isotopes | 35 |
| Radioactive Isotopes | 35 |
201Ra
| Abundance | Radioactive ☢️ |
|---|---|
| Relative Atomic Mass | |
| Mass Number | 201 |
| G-Factor | |
| Half Life | 20 ± 30 ms
|
| Spin | 3/2 |
| Quadrupole Moment | |
| Discovery Year | 2005 |
| Parity | - |
201Ra Decay Modes
| Decay Mode | Intensity |
|---|---|
| α (α emission) | 100% |
202Ra
| Abundance | Radioactive ☢️ |
|---|---|
| Relative Atomic Mass | |
| Mass Number | 202 |
| G-Factor | 0
|
| Half Life | 4.1 ± 1.1 ms
|
| Spin | 0 |
| Quadrupole Moment | 0
|
| Discovery Year | 2005 |
| Parity | + |
202Ra Decay Modes
| Decay Mode | Intensity |
|---|---|
| α (α emission) | 100% |
203Ra
| Abundance | Radioactive ☢️ |
|---|---|
| Relative Atomic Mass | |
| Mass Number | 203 |
| G-Factor | |
| Half Life | 36 ± 13 ms
|
| Spin | 3/2 |
| Quadrupole Moment | |
| Discovery Year | 1996 |
| Parity | - |
203Ra Decay Modes
| Decay Mode | Intensity |
|---|---|
| α (α emission) | 100% |
| β+ (β+ decay; β+ = ϵ + e+) | % |
204Ra
| Abundance | Radioactive ☢️ |
|---|---|
| Relative Atomic Mass | |
| Mass Number | 204 |
| G-Factor | 0
|
| Half Life | 60 ± 9 ms
|
| Spin | 0 |
| Quadrupole Moment | 0
|
| Discovery Year | 1995 |
| Parity | + |
204Ra Decay Modes
| Decay Mode | Intensity |
|---|---|
| α (α emission) | 100% |
| β+ (β+ decay; β+ = ϵ + e+) | % |
205Ra
| Abundance | Radioactive ☢️ |
|---|---|
| Relative Atomic Mass | |
| Mass Number | 205 |
| G-Factor | |
| Half Life | 220 ± 50 ms
|
| Spin | 3/2 |
| Quadrupole Moment | |
| Discovery Year | 1987 |
| Parity | - |
205Ra Decay Modes
| Decay Mode | Intensity |
|---|---|
| α (α emission) | 100% |
| β+ (β+ decay; β+ = ϵ + e+) | % |
206Ra
| Abundance | Radioactive ☢️ |
|---|---|
| Relative Atomic Mass | |
| Mass Number | 206 |
| G-Factor | 0
|
| Half Life | 240 ± 20 ms
|
| Spin | 0 |
| Quadrupole Moment | 0
|
| Discovery Year | 1967 |
| Parity | + |
206Ra Decay Modes
| Decay Mode | Intensity |
|---|---|
| α (α emission) | 100% |
| β+ (β+ decay; β+ = ϵ + e+) | % |
207Ra
| Abundance | Radioactive ☢️ |
|---|---|
| Relative Atomic Mass | |
| Mass Number | 207 |
| G-Factor | |
| Half Life | 1.38 ± 0.18 s
|
| Spin | 5/2 |
| Quadrupole Moment | |
| Discovery Year | 1967 |
| Parity | - |
207Ra Decay Modes
| Decay Mode | Intensity |
|---|---|
| α (α emission) | 86% |
| β+ (β+ decay; β+ = ϵ + e+) | % |
208Ra
| Abundance | Radioactive ☢️ |
|---|---|
| Relative Atomic Mass | |
| Mass Number | 208 |
| G-Factor | 0
|
| Half Life | 1.11 ± 0.045 s
|
| Spin | 0 |
| Quadrupole Moment | 0
|
| Discovery Year | 1967 |
| Parity | + |
208Ra Decay Modes
| Decay Mode | Intensity |
|---|---|
| α (α emission) | 87% |
| β+ (β+ decay; β+ = ϵ + e+) | % |
209Ra
| Abundance | Radioactive ☢️ |
|---|---|
| Relative Atomic Mass | |
| Mass Number | 209 |
| G-Factor | 0.3444 ± 0.0052
|
| Half Life | 4.71 ± 0.08 s
|
| Spin | 5/2 |
| Quadrupole Moment | 0.39 ± 0.04
|
| Discovery Year | 1967 |
| Parity | - |
209Ra Decay Modes
| Decay Mode | Intensity |
|---|---|
| α (α emission) | 100% |
| β+ (β+ decay; β+ = ϵ + e+) | % |
210Ra
| Abundance | Radioactive ☢️ |
|---|---|
| Relative Atomic Mass | |
| Mass Number | 210 |
| G-Factor | 0
|
| Half Life | 4 ± 0.1 s
|
| Spin | 0 |
| Quadrupole Moment | 0
|
| Discovery Year | 1967 |
| Parity | + |
210Ra Decay Modes
| Decay Mode | Intensity |
|---|---|
| α (α emission) | 100% |
| β+ (β+ decay; β+ = ϵ + e+) | % |
211Ra
| Abundance | Radioactive ☢️ |
|---|---|
| Relative Atomic Mass | |
| Mass Number | 211 |
| G-Factor | 0.3496 ± 0.0016
|
| Half Life | 12.6 ± 1.2 s
|
| Spin | 5/2 |
| Quadrupole Moment | 0.46 ± 0.04
|
| Discovery Year | 1967 |
| Parity | - |
211Ra Decay Modes
| Decay Mode | Intensity |
|---|---|
| α (α emission) | 100% |
| β+ (β+ decay; β+ = ϵ + e+) | % |
212Ra
| Abundance | Radioactive ☢️ |
|---|---|
| Relative Atomic Mass | |
| Mass Number | 212 |
| G-Factor | 0
|
| Half Life | 13 ± 0.2 s
|
| Spin | 0 |
| Quadrupole Moment | 0
|
| Discovery Year | 1967 |
| Parity | + |
212Ra Decay Modes
| Decay Mode | Intensity |
|---|---|
| α (α emission) | % |
| β+ (β+ decay; β+ = ϵ + e+) | % |
213Ra
| Abundance | Radioactive ☢️ |
|---|---|
| Relative Atomic Mass | |
| Mass Number | 213 |
| G-Factor | 1.22 ± 0.004
|
| Half Life | 2.73 ± 0.05 m
|
| Spin | 1/2 |
| Quadrupole Moment | 0
|
| Discovery Year | 1955 |
| Parity | - |
213Ra Decay Modes
| Decay Mode | Intensity |
|---|---|
| α (α emission) | 87% |
| β+ (β+ decay; β+ = ϵ + e+) | 13% |
214Ra
| Abundance | Radioactive ☢️ |
|---|---|
| Relative Atomic Mass | |
| Mass Number | 214 |
| G-Factor | 0
|
| Half Life | 2.437 ± 0.016 s
|
| Spin | 0 |
| Quadrupole Moment | 0
|
| Discovery Year | 1967 |
| Parity | + |
214Ra Decay Modes
| Decay Mode | Intensity |
|---|---|
| α (α emission) | 99.941% |
| β+ (β+ decay; β+ = ϵ + e+) | 0.059% |
215Ra
| Abundance | Radioactive ☢️ |
|---|---|
| Relative Atomic Mass | |
| Mass Number | 215 |
| G-Factor | |
| Half Life | 1.669 ± 0.009 ms
|
| Spin | 9/2 |
| Quadrupole Moment | |
| Discovery Year | 1967 |
| Parity | + |
215Ra Decay Modes
| Decay Mode | Intensity |
|---|---|
| α (α emission) | 100% |
216Ra
| Abundance | Radioactive ☢️ |
|---|---|
| Relative Atomic Mass | |
| Mass Number | 216 |
| G-Factor | 0
|
| Half Life | 172 ± 7 ns
|
| Spin | 0 |
| Quadrupole Moment | 0
|
| Discovery Year | 1972 |
| Parity | + |
216Ra Decay Modes
| Decay Mode | Intensity |
|---|---|
| α (α emission) | 100% |
| ϵ (electron capture) | 1% |
217Ra
| Abundance | Radioactive ☢️ |
|---|---|
| Relative Atomic Mass | |
| Mass Number | 217 |
| G-Factor | |
| Half Life | 1.95 ± 0.12 us
|
| Spin | 9/2 |
| Quadrupole Moment | |
| Discovery Year | 1970 |
| Parity | + |
217Ra Decay Modes
| Decay Mode | Intensity |
|---|---|
| α (α emission) | 100% |
218Ra
| Abundance | Radioactive ☢️ |
|---|---|
| Relative Atomic Mass | |
| Mass Number | 218 |
| G-Factor | 0
|
| Half Life | 25.91 ± 0.14 us
|
| Spin | 0 |
| Quadrupole Moment | 0
|
| Discovery Year | 1970 |
| Parity | + |
218Ra Decay Modes
| Decay Mode | Intensity |
|---|---|
| α (α emission) | 100% |
219Ra
| Abundance | Radioactive ☢️ |
|---|---|
| Relative Atomic Mass | |
| Mass Number | 219 |
| G-Factor | |
| Half Life | 9 ± 2 ms
|
| Spin | 7/2 |
| Quadrupole Moment | |
| Discovery Year | 1952 |
| Parity |
219Ra Decay Modes
| Decay Mode | Intensity |
|---|---|
| α (α emission) | 100% |
220Ra
| Abundance | Radioactive ☢️ |
|---|---|
| Relative Atomic Mass | |
| Mass Number | 220 |
| G-Factor | 0
|
| Half Life | 18.1 ± 1.2 ms
|
| Spin | 0 |
| Quadrupole Moment | 0
|
| Discovery Year | 1949 |
| Parity | + |
220Ra Decay Modes
| Decay Mode | Intensity |
|---|---|
| α (α emission) | 100% |
221Ra
| Abundance | Radioactive ☢️ |
|---|---|
| Relative Atomic Mass | |
| Mass Number | 221 |
| G-Factor | -0.0716 ± 0.00068
|
| Half Life | 25 ± 4 s
|
| Spin | 5/2 |
| Quadrupole Moment | 1.92 ± 0.06
|
| Discovery Year | 1949 |
| Parity | + |
221Ra Decay Modes
| Decay Mode | Intensity |
|---|---|
| α (α emission) | 100% |
| 14C | 1.2% |
222Ra
| Abundance | Radioactive ☢️ |
|---|---|
| Relative Atomic Mass | |
| Mass Number | 222 |
| G-Factor | 0
|
| Half Life | 33.6 ± 0.4 s
|
| Spin | 0 |
| Quadrupole Moment | 0
|
| Discovery Year | 1948 |
| Parity | + |
222Ra Decay Modes
| Decay Mode | Intensity |
|---|---|
| α (α emission) | 100% |
| 14C | 3% |
223Ra
| Abundance | Radioactive ☢️ |
|---|---|
| Relative Atomic Mass | |
| Mass Number | 223 |
| G-Factor | 0.17946666666667 ± 0.00053333333333333
|
| Half Life | 11.4352 ± 0.001 d
|
| Spin | 3/2 |
| Quadrupole Moment | 1.22 ± 0.03
|
| Discovery Year | 1905 |
| Parity | + |
223Ra Decay Modes
| Decay Mode | Intensity |
|---|---|
| α (α emission) | 100% |
| 14C | 8.9% |
224Ra
| Abundance | Radioactive ☢️ |
|---|---|
| Relative Atomic Mass | |
| Mass Number | 224 |
| G-Factor | 0
|
| Half Life | 3.6316 ± 0.0014 d
|
| Spin | 0 |
| Quadrupole Moment | 0
|
| Discovery Year | 1902 |
| Parity | + |
224Ra Decay Modes
| Decay Mode | Intensity |
|---|---|
| α (α emission) | 100% |
| 14C | 4% |
225Ra
| Abundance | Radioactive ☢️ |
|---|---|
| Relative Atomic Mass | |
| Mass Number | 225 |
| G-Factor | -1.46 ± 0.004
|
| Half Life | 14.82 ± 0.19 d
|
| Spin | 1/2 |
| Quadrupole Moment | 0
|
| Discovery Year | 1947 |
| Parity | + |
225Ra Decay Modes
| Decay Mode | Intensity |
|---|---|
| β− (β− decay) | 100% |
226Ra
| Abundance | Radioactive ☢️ |
|---|---|
| Relative Atomic Mass | |
| Mass Number | 226 |
| G-Factor | 0
|
| Half Life | 1.6 ± 0.007 ky
|
| Spin | 0 |
| Quadrupole Moment | 0
|
| Discovery Year | 1898 |
| Parity | + |
226Ra Decay Modes
| Decay Mode | Intensity |
|---|---|
| α (α emission) | 100% |
| 14C | 2.6% |
| 2β− (double β− decay) | % |
227Ra
| Abundance | Radioactive ☢️ |
|---|---|
| Relative Atomic Mass | |
| Mass Number | 227 |
| G-Factor | -0.26733333333333 ± 0.00073333333333333
|
| Half Life | 42.2 ± 0.5 m
|
| Spin | 3/2 |
| Quadrupole Moment | 1.53 ± 0.06
|
| Discovery Year | 1953 |
| Parity | + |
227Ra Decay Modes
| Decay Mode | Intensity |
|---|---|
| β− (β− decay) | 100% |
228Ra
| Abundance | Radioactive ☢️ |
|---|---|
| Relative Atomic Mass | |
| Mass Number | 228 |
| G-Factor | 0
|
| Half Life | 5.75 ± 0.03 y
|
| Spin | 0 |
| Quadrupole Moment | 0
|
| Discovery Year | 1907 |
| Parity | + |
228Ra Decay Modes
| Decay Mode | Intensity |
|---|---|
| β− (β− decay) | 100% |
229Ra
| Abundance | Radioactive ☢️ |
|---|---|
| Relative Atomic Mass | |
| Mass Number | 229 |
| G-Factor | 0.19968 ± 0.00056
|
| Half Life | 4 ± 0.2 m
|
| Spin | 5/2 |
| Quadrupole Moment | 2.99 ± 0.12
|
| Discovery Year | 1975 |
| Parity | + |
229Ra Decay Modes
| Decay Mode | Intensity |
|---|---|
| β− (β− decay) | 100% |
230Ra
| Abundance | Radioactive ☢️ |
|---|---|
| Relative Atomic Mass | |
| Mass Number | 230 |
| G-Factor | 0
|
| Half Life | 93 ± 2 m
|
| Spin | 0 |
| Quadrupole Moment | 0
|
| Discovery Year | 1978 |
| Parity | + |
230Ra Decay Modes
| Decay Mode | Intensity |
|---|---|
| β− (β− decay) | 100% |
231Ra
| Abundance | Radioactive ☢️ |
|---|---|
| Relative Atomic Mass | |
| Mass Number | 231 |
| G-Factor | -0.14216 ± 0.00044
|
| Half Life | 104 ± 1 s
|
| Spin | 5/2 |
| Quadrupole Moment | |
| Discovery Year | 1983 |
| Parity | + |
231Ra Decay Modes
| Decay Mode | Intensity |
|---|---|
| β− (β− decay) | 100% |
232Ra
| Abundance | Radioactive ☢️ |
|---|---|
| Relative Atomic Mass | |
| Mass Number | 232 |
| G-Factor | 0
|
| Half Life | 4 ± 0.3 m
|
| Spin | 0 |
| Quadrupole Moment | 0
|
| Discovery Year | 1983 |
| Parity | + |
232Ra Decay Modes
| Decay Mode | Intensity |
|---|---|
| β− (β− decay) | 100% |
233Ra
| Abundance | Radioactive ☢️ |
|---|---|
| Relative Atomic Mass | |
| Mass Number | 233 |
| G-Factor | |
| Half Life | 30 ± 5 s
|
| Spin | 1/2 |
| Quadrupole Moment | 0
|
| Discovery Year | 1990 |
| Parity | + |
233Ra Decay Modes
| Decay Mode | Intensity |
|---|---|
| β− (β− decay) | 100% |
234Ra
| Abundance | Radioactive ☢️ |
|---|---|
| Relative Atomic Mass | |
| Mass Number | 234 |
| G-Factor | 0
|
| Half Life | 30 ± 10 s
|
| Spin | 0 |
| Quadrupole Moment | 0
|
| Discovery Year | 1990 |
| Parity | + |
234Ra Decay Modes
| Decay Mode | Intensity |
|---|---|
| β− (β− decay) | 100% |
| β− SF (β−-delayed fission) | % |
History
Radium was discovered by Marie Curie and Pierre Curie in 1898. They extracted the radium compound from a uraninite sample. Radium was isolated in its metallic state by Marie Curie and André-Louis Debierne in 1910 through the electrolysis of radium chloride by using a mercury cathode and distilling in an atmosphere of hydrogen gas. From the Latin word radius meaning ray
| Discoverers | Pierre and Marie Curie |
|---|---|
| Discovery Location | France |
| Discovery Year | 1898 |
| Etymology (Name Origin) | Latin: radius (ray). |
| Pronunciation | RAY-di-em (English) |
Radium is highly radioactive and carcinogenic
Radium imparts a carmine red color to a flame
Uses
Radium was formerly used in self-luminous paints for watches, nuclear panels, aircraft switches, clocks, and instrument dials. Radium chloride was used in medicine to produce radon gas which in turn was used as a cancer treatment. The isotope 223Ra is currently under investigation for use in medicine as a cancer treatment of bone metastasis. Used in treating cancer because of the gamma rays it gives off.
