| Atomic Number | 91 |
|---|---|
| Atomic Weight | 231.03588 |
| Mass Number | 231 |
| Group | |
|---|---|
| Period | 7 |
| Block | f |
| Protons | 91 p+ |
|---|---|
| Neutrons | 140 n0 |
| Electrons | 91 e- |
| Atomic Radius | |
|---|---|
| Molar Volume | |
| Covalent Radius | |
| Metallic Radius | |
| Ionic Radius | |
| Crystal Radius | |
| Van der Waals Radius | |
| Density |
| Energy | |
|---|---|
| Proton Affinity | |
| Electron Affinity | |
| Ionization Energy | |
| Heat of Vaporization | |
| Heat of Fusion | |
| Heat of Formation | |
| Electrons | |
| Electron Shells | 2, 8, 18, 32, 20, 9, 2 |
| Valence Electrons | 2 ⓘ |
| Electron Configuration | [Rn] 5f2 6d1 7s2ⓘ 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d10 6p6 5f2 6d1 7s2 |
| Oxidation States | 2, 3, 4, 5 |
| Electronegativity |
1.5
|
| Electrophilicity Index | |
| States of Matter | |
| Phase | {ERROR}|
| Gas Phase | |
| Boiling Point | |
| Melting Point | |
| Critical Pressure | |
| Critical Temperature | |
| Triple Point | |
| Visual | |
Protactinium is a Black. Pa has a CPK of #ffffff, Jmol of #00a1ff, and MOLCAS GV of #00a1ff. The Appearance of Element 91 is bright, silvery metallic luster. | |
| Color | Black
|
| Appearance | bright, silvery metallic luster |
| 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 | |
| Electrical Resistivity | |
| Superconducting Point | |
| Magnetism | |
| Type | paramagnetic |
| Magnetic Susceptibility (Mass) | 0.0000000325 m³/Kg
|
| Magnetic Susceptibility (Molar) | 0.000000007509 m³/mol
|
| Magnetic Susceptibility (Volume) | 0.0004995
|
| Magnetic Ordering | |
| Curie Point | |
| Neel Point | |
| Structure | |
The Crystal Structure of Protactinium is TET. The lattice constant of Pa is 3.92 Å. The lattice angles of Element 91 are π/2, π/2, π/2. | |
| Crystal Structure | {ERROR} |
| Lattice Constant | |
| Lattice Angles | π/2, π/2, π/2 |
| Mechanical Properties | |
| Hardness | |
| Bulk Modulus | |
| Shear Modulus | |
| Young's Modulus | |
| Poisson Ratio | |
| Speed of Sound | |
| Classification | |
The Glawe Number of Protactinium is 35. The Mendeleev Number of Pa is 18. The Pettifor Number of Element 91 is 46. The Geochemical Class of Protactinium (Pa) is U/Th decay series. The Goldschmidt Class of Protactinium is litophile. | |
| Category | Actinides, Actinides |
| CAS Group | |
| IUPAC Group | |
| Glawe Number | 35 |
| Mendeleev Number | 18 |
| Pettifor Number | 46 |
| Geochemical Class | U/Th decay series |
| Goldschmidt Class | litophile |
The Dipole Polarizability of Protactinium is 154 plus or minus 20 a₀. The Allotropes of Pa is . The Neutron Cross Section of Element 91 is 200. The Quantum Numbers of Protactinium (Pa) is 4K11/2. The Space Group of Protactinium is 139 (I4/mmm).
| Gas Basicity | |
|---|---|
| Dipole Polarizability | |
| C6 Dispersion Coefficient | |
| Allotropes | |
| Neutron Cross Section | 200
|
| Neutron Mass Absorption | |
| Quantum Numbers | 4K11/2 |
| Space Group | 139 (I4/mmm) |
| Stable Isotopes | 0 |
|---|---|
| Unstable Isotopes | 31 |
| Natural Isotopes | 1 |
| Mass Number | 211 |
|---|---|
| Neutron Number | 120 |
| Relative Atomic Mass | |
| G-Factor | |
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 6 ± 3 ms
|
| Spin | 9/2 |
| Quadrupole Moment | |
| Discovery Year | 2006 |
| Parity | - |
| Decay Mode | Intensity |
|---|---|
| α (α emission) | 100% |
| β+ (β+ decay; β+ = ϵ + e+) | |
| p (proton emission) |
| Mass Number | 212 |
|---|---|
| Neutron Number | 121 |
| Relative Atomic Mass | |
| G-Factor | |
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 5.8 ± 1.9 ms
|
| Spin | 3 |
| Quadrupole Moment | |
| Discovery Year | 1997 |
| Parity | + |
| Decay Mode | Intensity |
|---|---|
| α (α emission) | 100% |
| Mass Number | 213 |
|---|---|
| Neutron Number | 122 |
| Relative Atomic Mass | |
| G-Factor | |
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 7.4 ± 2.4 ms
|
| Spin | 9/2 |
| Quadrupole Moment | |
| Discovery Year | 1995 |
| Parity | - |
| Decay Mode | Intensity |
|---|---|
| α (α emission) | 100% |
| Mass Number | 214 |
|---|---|
| Neutron Number | 123 |
| Relative Atomic Mass | |
| G-Factor | |
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 17 ± 3 ms
|
| Spin | 7 |
| Quadrupole Moment | |
| Discovery Year | 1995 |
| Parity | + |
| Decay Mode | Intensity |
|---|---|
| α (α emission) | 100% |
| Mass Number | 215 |
|---|---|
| Neutron Number | 124 |
| Relative Atomic Mass | |
| G-Factor | |
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 14 ± 2 ms
|
| Spin | 9/2 |
| Quadrupole Moment | |
| Discovery Year | 1979 |
| Parity | - |
| Decay Mode | Intensity |
|---|---|
| α (α emission) | 100% |
| Mass Number | 216 |
|---|---|
| Neutron Number | 125 |
| Relative Atomic Mass | |
| G-Factor | |
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 105 ± 12 ms
|
| Spin | 5 |
| Quadrupole Moment | |
| Discovery Year | 1972 |
| Parity | + |
| Decay Mode | Intensity |
|---|---|
| α (α emission) | 100% |
| β+ (β+ decay; β+ = ϵ + e+) |
| Mass Number | 217 |
|---|---|
| Neutron Number | 126 |
| Relative Atomic Mass | |
| G-Factor | |
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 3.8 ± 0.2 ms
|
| Spin | 9/2 |
| Quadrupole Moment | |
| Discovery Year | 1968 |
| Parity | - |
| Decay Mode | Intensity |
|---|---|
| α (α emission) | 100% |
| β− (β− decay) |
| Mass Number | 218 |
|---|---|
| Neutron Number | 127 |
| Relative Atomic Mass | |
| G-Factor | |
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 108 ± 5 us
|
| Spin | 8 |
| Quadrupole Moment | |
| Discovery Year | 1979 |
| Parity | - |
| Decay Mode | Intensity |
|---|---|
| α (α emission) | 100% |
| Mass Number | 219 |
|---|---|
| Neutron Number | 128 |
| Relative Atomic Mass | |
| G-Factor | |
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 56 ± 9 ns
|
| Spin | 9/2 |
| Quadrupole Moment | |
| Discovery Year | 2005 |
| Parity | - |
| Decay Mode | Intensity |
|---|---|
| α (α emission) | 100% |
| β+ (β+ decay; β+ = ϵ + e+) |
| Mass Number | 220 |
|---|---|
| Neutron Number | 129 |
| Relative Atomic Mass | |
| G-Factor | |
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 0.85 ± 0.06 us
|
| Spin | 1 |
| Quadrupole Moment | |
| Discovery Year | 2005 |
| Parity | - |
| Decay Mode | Intensity |
|---|---|
| α (α emission) | 100% |
| β+ (β+ decay; β+ = ϵ + e+) |
| Mass Number | 221 |
|---|---|
| Neutron Number | 130 |
| Relative Atomic Mass | |
| G-Factor | |
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 5.9 ± 1.7 us
|
| Spin | 9/2 |
| Quadrupole Moment | |
| Discovery Year | 1983 |
| Parity | - |
| Decay Mode | Intensity |
|---|---|
| α (α emission) | 100% |
| Mass Number | 222 |
|---|---|
| Neutron Number | 131 |
| Relative Atomic Mass | |
| G-Factor | |
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 3.8 ± 0.2 ms
|
| Spin | 1 |
| Quadrupole Moment | |
| Discovery Year | 1970 |
| Parity | - |
| Decay Mode | Intensity |
|---|---|
| α (α emission) | 100% |
| Mass Number | 223 |
|---|---|
| Neutron Number | 132 |
| Relative Atomic Mass | |
| G-Factor | |
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 5.3 ± 0.3 ms
|
| Spin | 9/2 |
| Quadrupole Moment | |
| Discovery Year | 1970 |
| Parity | - |
| Decay Mode | Intensity |
|---|---|
| α (α emission) | 100% |
| β+ (β+ decay; β+ = ϵ + e+) |
| Mass Number | 224 |
|---|---|
| Neutron Number | 133 |
| Relative Atomic Mass | |
| G-Factor | |
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 844 ± 19 ms
|
| Spin | 5 |
| Quadrupole Moment | |
| Discovery Year | 1958 |
| Parity | - |
| Decay Mode | Intensity |
|---|---|
| α (α emission) | 100% |
| β+ (β+ decay; β+ = ϵ + e+) |
| Mass Number | 225 |
|---|---|
| Neutron Number | 134 |
| Relative Atomic Mass | |
| G-Factor | |
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 1.71 ± 0.1 s
|
| Spin | 5/2 |
| Quadrupole Moment | |
| Discovery Year | 1958 |
| Parity | - |
| Decay Mode | Intensity |
|---|---|
| α (α emission) | 100% |
| Mass Number | 226 |
|---|---|
| Neutron Number | 135 |
| Relative Atomic Mass | |
| G-Factor | |
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 1.8 ± 0.2 m
|
| Spin | 1 |
| Quadrupole Moment | |
| Discovery Year | 1949 |
| Parity | - |
| Decay Mode | Intensity |
|---|---|
| α (α emission) | 74% |
| β+ (β+ decay; β+ = ϵ + e+) | 26% |
| Mass Number | 227 |
|---|---|
| Neutron Number | 136 |
| Relative Atomic Mass | |
| G-Factor | |
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 38.3 ± 0.3 m
|
| Spin | 5/2 |
| Quadrupole Moment | |
| Discovery Year | 1948 |
| Parity | - |
| Decay Mode | Intensity |
|---|---|
| α (α emission) | 85% |
| ϵ (electron capture) | 15% |
| Mass Number | 228 |
|---|---|
| Neutron Number | 137 |
| Relative Atomic Mass | |
| G-Factor | 1.1666666666667 ± 0.16666666666667
|
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 22 ± 1 h
|
| Spin | 3 |
| Quadrupole Moment | |
| Discovery Year | 1948 |
| Parity | + |
| Decay Mode | Intensity |
|---|---|
| β+ (β+ decay; β+ = ϵ + e+) | 98.15% |
| α (α emission) | 1.85% |
| Mass Number | 229 |
|---|---|
| Neutron Number | 138 |
| Relative Atomic Mass | |
| G-Factor | |
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 1.55 ± 0.04 d
|
| Spin | 5/2 |
| Quadrupole Moment | |
| Discovery Year | 1949 |
| Parity | + |
| Decay Mode | Intensity |
|---|---|
| ϵ (electron capture) | 99.51% |
| α (α emission) | 0.49% |
| Mass Number | 230 |
|---|---|
| Neutron Number | 139 |
| Relative Atomic Mass | |
| G-Factor | 1 ± 0.1
|
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 17.4 ± 0.5 d
|
| Spin | 2 |
| Quadrupole Moment | |
| Discovery Year | 1948 |
| Parity | - |
| Decay Mode | Intensity |
|---|---|
| β+ (β+ decay; β+ = ϵ + e+) | 92.2% |
| β− (β− decay) | 7.8% |
| α (α emission) | 0.0032% |
| Mass Number | 231 |
|---|---|
| Neutron Number | 140 |
| Relative Atomic Mass | |
| G-Factor | 1.3266666666667 ± 0.013333333333333
|
| Abundance | 100
|
| Radioactivity | ☢️ Radioactive |
| Half Life | 32.65 ± 0.2 ky
|
| Spin | 3/2 |
| Quadrupole Moment | -1.72 ± 0.05
|
| Discovery Year | 1918 |
| Parity | - |
| Decay Mode | Intensity |
|---|---|
| α (α emission) | 100% |
| SF (spontaneous fission) | 3% |
| 24Ne (heavy cluster emission) | 13.4% |
| 23F | 9.9% |
| Mass Number | 232 |
|---|---|
| Neutron Number | 141 |
| Relative Atomic Mass | |
| G-Factor | |
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 1.32 ± 0.02 d
|
| Spin | 2 |
| Quadrupole Moment | |
| Discovery Year | 1949 |
| Parity | - |
| Decay Mode | Intensity |
|---|---|
| β− (β− decay) | 100% |
| ϵ (electron capture) |
| Mass Number | 233 |
|---|---|
| Neutron Number | 142 |
| Relative Atomic Mass | |
| G-Factor | 2.6666666666667 ± 0.46666666666667
|
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 26.975 ± 0.013 d
|
| Spin | 3/2 |
| Quadrupole Moment | -3 ± 0.4
|
| Discovery Year | 1938 |
| Parity | - |
| Decay Mode | Intensity |
|---|---|
| β− (β− decay) | 100% |
| Mass Number | 234 |
|---|---|
| Neutron Number | 143 |
| Relative Atomic Mass | |
| G-Factor | |
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 6.7 ± 0.05 h
|
| Spin | 4 |
| Quadrupole Moment | |
| Discovery Year | 1913 |
| Parity | + |
| Decay Mode | Intensity |
|---|---|
| β− (β− decay) | 100% |
| Mass Number | 235 |
|---|---|
| Neutron Number | 144 |
| Relative Atomic Mass | |
| G-Factor | |
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 24.4 ± 0.2 m
|
| Spin | 3/2 |
| Quadrupole Moment | |
| Discovery Year | 1950 |
| Parity | - |
| Decay Mode | Intensity |
|---|---|
| β− (β− decay) | 100% |
| Mass Number | 236 |
|---|---|
| Neutron Number | 145 |
| Relative Atomic Mass | |
| G-Factor | |
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 9.1 ± 0.1 m
|
| Spin | 1 |
| Quadrupole Moment | |
| Discovery Year | 1963 |
| Parity |
| Decay Mode | Intensity |
|---|---|
| β− (β− decay) | 100% |
| β− SF (β−-delayed fission) | 6% |
| Mass Number | 237 |
|---|---|
| Neutron Number | 146 |
| Relative Atomic Mass | |
| G-Factor | |
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 8.7 ± 0.2 m
|
| Spin | 1/2 |
| Quadrupole Moment | 0
|
| Discovery Year | 1954 |
| Parity | + |
| Decay Mode | Intensity |
|---|---|
| β− (β− decay) | 100% |
| Mass Number | 238 |
|---|---|
| Neutron Number | 147 |
| Relative Atomic Mass | |
| G-Factor | |
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 2.28 ± 0.09 m
|
| Spin | 3 |
| Quadrupole Moment | |
| Discovery Year | 1968 |
| Parity | - |
| Decay Mode | Intensity |
|---|---|
| β− (β− decay) | 100% |
| β− SF (β−-delayed fission) | 2.6% |
| Mass Number | 239 |
|---|---|
| Neutron Number | 148 |
| Relative Atomic Mass | |
| G-Factor | |
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | 1.8 ± 0.5 h
|
| Spin | 1/2 |
| Quadrupole Moment | 0
|
| Discovery Year | 1995 |
| Parity | + |
| Decay Mode | Intensity |
|---|---|
| β− (β− decay) | 100% |
| Mass Number | 240 |
|---|---|
| Neutron Number | 149 |
| Relative Atomic Mass | |
| G-Factor | |
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | |
| Spin | 3 |
| Quadrupole Moment | |
| Discovery Year | |
| Parity | + |
| Decay Mode | Intensity |
|---|---|
| β− (β− decay) |
| Mass Number | 241 |
|---|---|
| Neutron Number | 150 |
| Relative Atomic Mass | |
| G-Factor | |
| Abundance | |
| Radioactivity | ☢️ Radioactive |
| Half Life | |
| Spin | 1/2 |
| Quadrupole Moment | 0
|
| Discovery Year | |
| Parity | + |
| Decay Mode | Intensity |
|---|---|
| β− (β− decay) |
In 1900, William Crookes isolated protactinium as an intensely radioactive material from uranium Protactinium was first identified in 1913 by Kasimir Fajans and Oswald Helmuth Göhring in Germany. A more stable isotope of protactinium was discovered in 1917 by Otto Hahn and Lise Meitner at the Kaiser Wilhelm Institute in Berlin. From the Greek protos meaning first
| Discoverers | Fredrich Soddy, John Cranston, Otto Hahn, Lise Meitner |
|---|---|
| Discovery Location | England/France |
| Discovery Year | 1917 |
| Etymology (Name Origin) | Greek: proto and actinium (parent of actinium); it forms actinium when it radioactively decays. |
| Pronunciation | PRO-tak-tin-eh-em (English) |
Does not occur in nature. Found among fission products of uranium, thorium, and plutonium.
| Abundance | |
|---|---|
| Abundance in Earth's crust | |
| Natural Abundance (Oceans) | |
| Natural Abundance (Human Body) | 0 %
|
| Natural Abundance (Meteor) | |
| Natural Abundance (Sun) | |
| Abundance in Universe | 0 %
|