Atomic Number | 90 |
---|---|
Atomic Weight | 232.0377 |
Mass Number | 232 |
Group | |
---|---|
Period | 7 |
Block | f |
Protons | 90 p+ |
---|---|
Neutrons | 142 n0 |
Electrons | 90 e- |
Atomic Radius | 180 pm
|
---|---|
Molar Volume | 19.8 cm³/mol
|
Covalent Radius | 175 pm
|
Metallic Radius | |
Ionic Radius | 94 pm
|
Crystal Radius | 108 pm
|
Van der Waals Radius | 245 pm
|
Density | 11.7 g/cm³
|
Energy | |
Proton Affinity | |
Electron Affinity | |
Ionization Energy | 6.3067 eV/particle
|
Heat of Vaporization | 513.7 kJ/mol
|
Heat of Fusion | 16.11 kJ/mol
|
Heat of Formation | 602 kJ/mol
|
Electrons | |
Electron Shells | 2, 8, 18, 32, 18, 10, 2 |
Valence Electrons | 4 |
Electron Configuration | [Rn] 6d2 7s2 |
Oxidation States | -1, 1, 2, 3, 4 |
Electronegativity |
1.3
|
Electrophilicity | |
Phases | |
Phase | Solid |
Gas Phase | |
Boiling Point | 5,058.15 K
|
Melting Point | 2,023.15 K
|
Critical Pressure | |
Critical Temperature | |
Triple Point | |
Visual | |
Color | Silver
|
Appearance | silvery, often with black tarnish |
Refractive Index | |
Thermodynamic Properties | |
Thermal Conductivity | |
Thermal Expansion | 0.000011 1/K
|
Molar Heat Capacity | 27.32 J/(mol K)
|
Specific Heat Capacity | 0.118 J/(g⋅K)
|
Heat Capacity Ratio (Adiabatic Index) | |
Electrical Properties | |
Type | Conductor |
Electrical Conductivity | 6.7 MS/m
|
Electrical Resistivity | 0.00000015 m Ω
|
Superconducting Point | 1.38 K
|
Magnetism | |
Type | paramagnetic |
Magnetic Susceptibility (Mass) | 0.0000000072 m³/Kg
|
Magnetic Susceptibility (Molar) | 0.0000000017 m³/mol
|
Magnetic Susceptibility (Volume) | 0.000084
|
Magnetic Ordering | |
Curie Point | |
Neel Point | |
Structure | |
Crystal Structure | Face Centered Cubic (FCC) |
Lattice Constant | 5.08 Å
|
Lattice Angles | π/2, π/2, π/2 |
Mechanical Properties | |
Hardness | 3 MPa
|
Bulk Modulus | 54 GPa
|
Shear Modulus | 31 GPa
|
Young Modulus | 79 GPa
|
Poisson Ratio | 0.27
|
Speed of Sound | 2,490 m/s
|
Classification | |
Category | Actinides, Actinides |
CAS Group | |
IUPAC Group | |
Glawe Number | 34 |
Mendeleev Number | 16 |
Pettifor Number | 47 |
Geochemical Class | rare earth & related |
Goldschmidt Class | litophile |
Other | |
Gas Basicity | |
Dipole Polarizability | |
C6 Dispersion Coefficient | |
Allotropes | |
Neutron Cross Section | 7.4
|
Neutron Mass Absorption | 0.001
|
Quantum Numbers | 3F2 |
Space Group | 225 (Fm_3m) |
Stable Isotopes | 2 |
---|---|
Unstable Isotopes | 30 |
Radioactive Isotopes | 32 |
Abundance | Radioactive ☢️ |
---|---|
Relative Atomic Mass | |
Mass Number | 208 |
G-Factor | 0
|
Half Life | 2.4 ± 1.2 ms
|
Spin | 0 |
Quadrupole Moment | 0
|
Discovery Year | 2010 |
Parity | + |
Decay Mode | Intensity |
---|---|
α (α emission) | 100% |
Abundance | Radioactive ☢️ |
---|---|
Relative Atomic Mass | |
Mass Number | 209 |
G-Factor | |
Half Life | |
Spin | 5/2 |
Quadrupole Moment | |
Discovery Year | |
Parity | - |
Decay Mode | Intensity |
---|---|
α (α emission) | % |
β+ (β+ decay; β+ = ϵ + e+) | % |
Abundance | Radioactive ☢️ |
---|---|
Relative Atomic Mass | |
Mass Number | 210 |
G-Factor | 0
|
Half Life | 16 ± 3.6 ms
|
Spin | 0 |
Quadrupole Moment | 0
|
Discovery Year | 1995 |
Parity | + |
Decay Mode | Intensity |
---|---|
α (α emission) | 100% |
β+ (β+ decay; β+ = ϵ + e+) | % |
Abundance | Radioactive ☢️ |
---|---|
Relative Atomic Mass | |
Mass Number | 211 |
G-Factor | |
Half Life | 48 ± 20 ms
|
Spin | 5/2 |
Quadrupole Moment | |
Discovery Year | 1995 |
Parity | - |
Decay Mode | Intensity |
---|---|
α (α emission) | 100% |
β+ (β+ decay; β+ = ϵ + e+) | % |
Abundance | Radioactive ☢️ |
---|---|
Relative Atomic Mass | |
Mass Number | 212 |
G-Factor | 0
|
Half Life | 31.7 ± 1.3 ms
|
Spin | 0 |
Quadrupole Moment | 0
|
Discovery Year | 1980 |
Parity | + |
Decay Mode | Intensity |
---|---|
α (α emission) | 100% |
β+ (β+ decay; β+ = ϵ + e+) | % |
Abundance | Radioactive ☢️ |
---|---|
Relative Atomic Mass | |
Mass Number | 213 |
G-Factor | |
Half Life | 144 ± 21 ms
|
Spin | 5/2 |
Quadrupole Moment | |
Discovery Year | 1968 |
Parity | - |
Decay Mode | Intensity |
---|---|
α (α emission) | 100% |
β+ (β+ decay; β+ = ϵ + e+) | % |
Abundance | Radioactive ☢️ |
---|---|
Relative Atomic Mass | |
Mass Number | 214 |
G-Factor | 0
|
Half Life | 87 ± 10 ms
|
Spin | 0 |
Quadrupole Moment | 0
|
Discovery Year | 1968 |
Parity | + |
Decay Mode | Intensity |
---|---|
α (α emission) | 100% |
β+ (β+ decay; β+ = ϵ + e+) | % |
Abundance | Radioactive ☢️ |
---|---|
Relative Atomic Mass | |
Mass Number | 215 |
G-Factor | |
Half Life | 1.35 ± 0.14 s
|
Spin | 1/2 |
Quadrupole Moment | 0
|
Discovery Year | 1968 |
Parity | - |
Decay Mode | Intensity |
---|---|
α (α emission) | 100% |
Abundance | Radioactive ☢️ |
---|---|
Relative Atomic Mass | |
Mass Number | 216 |
G-Factor | 0
|
Half Life | 26.28 ± 0.16 ms
|
Spin | 0 |
Quadrupole Moment | 0
|
Discovery Year | 1968 |
Parity | + |
Decay Mode | Intensity |
---|---|
α (α emission) | 100% |
β+ (β+ decay; β+ = ϵ + e+) | % |
Abundance | Radioactive ☢️ |
---|---|
Relative Atomic Mass | |
Mass Number | 217 |
G-Factor | |
Half Life | 248 ± 4 us
|
Spin | 9/2 |
Quadrupole Moment | |
Discovery Year | 1968 |
Parity | + |
Decay Mode | Intensity |
---|---|
α (α emission) | 100% |
Abundance | Radioactive ☢️ |
---|---|
Relative Atomic Mass | |
Mass Number | 218 |
G-Factor | 0
|
Half Life | 122 ± 5 ns
|
Spin | 0 |
Quadrupole Moment | 0
|
Discovery Year | 1973 |
Parity | + |
Decay Mode | Intensity |
---|---|
α (α emission) | 100% |
Abundance | Radioactive ☢️ |
---|---|
Relative Atomic Mass | |
Mass Number | 219 |
G-Factor | |
Half Life | 1.023 ± 0.018 us
|
Spin | 9/2 |
Quadrupole Moment | |
Discovery Year | 1973 |
Parity | + |
Decay Mode | Intensity |
---|---|
α (α emission) | 100% |
β+ (β+ decay; β+ = ϵ + e+) | % |
Abundance | Radioactive ☢️ |
---|---|
Relative Atomic Mass | |
Mass Number | 220 |
G-Factor | 0
|
Half Life | 10.2 ± 0.3 us
|
Spin | 0 |
Quadrupole Moment | 0
|
Discovery Year | 1973 |
Parity | + |
Decay Mode | Intensity |
---|---|
α (α emission) | 100% |
ϵ (electron capture) | % |
Abundance | Radioactive ☢️ |
---|---|
Relative Atomic Mass | |
Mass Number | 221 |
G-Factor | |
Half Life | 1.75 ± 0.02 ms
|
Spin | 7/2 |
Quadrupole Moment | |
Discovery Year | 1970 |
Parity | + |
Decay Mode | Intensity |
---|---|
α (α emission) | 100% |
Abundance | Radioactive ☢️ |
---|---|
Relative Atomic Mass | |
Mass Number | 222 |
G-Factor | 0
|
Half Life | 2.24 ± 0.03 ms
|
Spin | 0 |
Quadrupole Moment | 0
|
Discovery Year | 1970 |
Parity | + |
Decay Mode | Intensity |
---|---|
α (α emission) | 100% |
ϵ (electron capture) | % |
Abundance | Radioactive ☢️ |
---|---|
Relative Atomic Mass | |
Mass Number | 223 |
G-Factor | |
Half Life | 600 ± 20 ms
|
Spin | 5/2 |
Quadrupole Moment | |
Discovery Year | 1952 |
Parity |
Decay Mode | Intensity |
---|---|
α (α emission) | 100% |
Abundance | Radioactive ☢️ |
---|---|
Relative Atomic Mass | |
Mass Number | 224 |
G-Factor | 0
|
Half Life | 1.04 ± 0.02 s
|
Spin | 0 |
Quadrupole Moment | 0
|
Discovery Year | 1949 |
Parity | + |
Decay Mode | Intensity |
---|---|
α (α emission) | 100% |
2β+ (double β+ decay) | % |
Abundance | Radioactive ☢️ |
---|---|
Relative Atomic Mass | |
Mass Number | 225 |
G-Factor | |
Half Life | 8.75 ± 0.04 m
|
Spin | 3/2 |
Quadrupole Moment | |
Discovery Year | 1949 |
Parity | + |
Decay Mode | Intensity |
---|---|
α (α emission) | 90% |
ϵ (electron capture) | % |
Abundance | Radioactive ☢️ |
---|---|
Relative Atomic Mass | |
Mass Number | 226 |
G-Factor | 0
|
Half Life | 30.7 ± 0.03 m
|
Spin | 0 |
Quadrupole Moment | 0
|
Discovery Year | 1948 |
Parity | + |
Decay Mode | Intensity |
---|---|
α (α emission) | 100% |
18O | 3.2% |
Abundance | Radioactive ☢️ |
---|---|
Relative Atomic Mass | |
Mass Number | 227 |
G-Factor | |
Half Life | 18.693 ± 0.004 d
|
Spin | 1/2 |
Quadrupole Moment | 0
|
Discovery Year | 1906 |
Parity | + |
Decay Mode | Intensity |
---|---|
α (α emission) | 100% |
Abundance | Radioactive ☢️ |
---|---|
Relative Atomic Mass | |
Mass Number | 228 |
G-Factor | 0
|
Half Life | 1.9125 ± 0.0007 y
|
Spin | 0 |
Quadrupole Moment | 0
|
Discovery Year | 1905 |
Parity | + |
Decay Mode | Intensity |
---|---|
α (α emission) | 100% |
20O | 1.13% |
Abundance | Radioactive ☢️ |
---|---|
Relative Atomic Mass | |
Mass Number | 229 |
G-Factor | 0.184 ± 0.016
|
Half Life | 7.916 ± 0.017 ky
|
Spin | 5/2 |
Quadrupole Moment | 3.11 ± 0.06
|
Discovery Year | 1947 |
Parity | + |
Decay Mode | Intensity |
---|---|
α (α emission) | 100% |
Abundance | Radioactive ☢️ 0.02 ± 0.02
|
---|---|
Relative Atomic Mass | |
Mass Number | 230 |
G-Factor | 0
|
Half Life | 75.4 ± 0.3 ky
|
Spin | 0 |
Quadrupole Moment | 0
|
Discovery Year | 1907 |
Parity | + |
Decay Mode | Intensity |
---|---|
α (α emission) | 100% |
SF (spontaneous fission) | 4% |
24Ne (heavy cluster emission) | 5.8% |
Abundance | Radioactive ☢️ |
---|---|
Relative Atomic Mass | |
Mass Number | 231 |
G-Factor | |
Half Life | 25.52 ± 0.01 h
|
Spin | 5/2 |
Quadrupole Moment | |
Discovery Year | 1911 |
Parity | + |
Decay Mode | Intensity |
---|---|
β− (β− decay) | 100% |
Abundance | Radioactive ☢️ 99.98 ± 0.02
|
---|---|
Relative Atomic Mass | |
Mass Number | 232 |
G-Factor | 0
|
Half Life | 14 ± 0.1 Gy
|
Spin | 0 |
Quadrupole Moment | 0
|
Discovery Year | 1898 |
Parity | + |
Decay Mode | Intensity |
---|---|
α (α emission) | 100% |
SF (spontaneous fission) | 1.1% |
26Ne | 2.78% |
2β− (double β− decay) | % |
Abundance | Radioactive ☢️ |
---|---|
Relative Atomic Mass | |
Mass Number | 233 |
G-Factor | |
Half Life | 21.83 ± 0.04 m
|
Spin | 1/2 |
Quadrupole Moment | 0
|
Discovery Year | 1935 |
Parity | + |
Decay Mode | Intensity |
---|---|
β− (β− decay) | 100% |
Abundance | Radioactive ☢️ |
---|---|
Relative Atomic Mass | |
Mass Number | 234 |
G-Factor | 0
|
Half Life | 24.107 ± 0.024 d
|
Spin | 0 |
Quadrupole Moment | 0
|
Discovery Year | 1900 |
Parity | + |
Decay Mode | Intensity |
---|---|
β− (β− decay) | 100% |
α (α emission) | % |
Abundance | Radioactive ☢️ |
---|---|
Relative Atomic Mass | |
Mass Number | 235 |
G-Factor | |
Half Life | 7.2 ± 0.1 m
|
Spin | 1/2 |
Quadrupole Moment | 0
|
Discovery Year | 1969 |
Parity | + |
Decay Mode | Intensity |
---|---|
β− (β− decay) | 100% |
Abundance | Radioactive ☢️ |
---|---|
Relative Atomic Mass | |
Mass Number | 236 |
G-Factor | 0
|
Half Life | 37.3 ± 1.5 m
|
Spin | 0 |
Quadrupole Moment | 0
|
Discovery Year | 1973 |
Parity | + |
Decay Mode | Intensity |
---|---|
β− (β− decay) | 100% |
Abundance | Radioactive ☢️ |
---|---|
Relative Atomic Mass | |
Mass Number | 237 |
G-Factor | |
Half Life | 4.8 ± 0.5 m
|
Spin | 5/2 |
Quadrupole Moment | |
Discovery Year | 1993 |
Parity | + |
Decay Mode | Intensity |
---|---|
β− (β− decay) | 100% |
Abundance | Radioactive ☢️ |
---|---|
Relative Atomic Mass | |
Mass Number | 238 |
G-Factor | 0
|
Half Life | 9.4 ± 2 m
|
Spin | 0 |
Quadrupole Moment | 0
|
Discovery Year | 1999 |
Parity | + |
Decay Mode | Intensity |
---|---|
β− (β− decay) | 100% |
Thorium was discovered by Jöns Jacob Berzelius in 1828, in Stockholm, Sweden. Thorium was first observed to be radioactive in 1898, independently, by Polish-French physicist Marie Curie and German chemist Gerhard Carl Schmidt. The crystal bar process was discovered by Anton Eduard van Arkel and Jan Hendrik de Boer in 1925 to produce high-purity metallic thorium. Named after Thor, Scandinavian god of war
Discoverers | Jöns Berzelius |
---|---|
Discovery Location | Sweden |
Discovery Year | 1828 |
Etymology (Name Origin) | Named for Thor, Norse god of thunder. |
Pronunciation | THOR-i-em (English) |