| Vrstno število | 99 | 
|---|---|
| Atomska teža | 252 | 
| Masno število | 239 | 
| Skupina | |
|---|---|
| Perioda | 7 | 
| Blok | f | 
| proton | 99 p+ | 
|---|---|
| nevtron | 140 n0 | 
| elektron | 99 e- | 
| Atomski Polmer | |
|---|---|
| Molarna prostornina | |
| Kovalentni Polmer | |
| Metallic Radius | |
| Ionski polmer | |
| Crystal Radius | |
| Van der Waalsov polmer | |
| density | 
| energija | |
|---|---|
| proton affinity | |
| Elektronska afiniteta | |
| ionization energy | |
| Izparilna toplota | |
| talilna toplota | |
| Standardna tvorbena entalpija | |
| elektron | |
| Elektronska lupina | 2, 8, 18, 32, 29, 8, 2 | 
| valence electron | 2 ⓘ | 
| elektronska konfiguracija | [Rn] 5f11 7s2ⓘ 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d10 6p6 5f11 7s2 | 
| Oksidacijsko stanje | 2, 3, 4 | 
| Elektronegativnost | |
| Electrophilicity Index | |
| osnovno agregatno stanje | |
| phase of matter{ERROR} | |
| plinasto agregatno stanje | |
| Vrelišče | |
| Tališče | |
| critical pressure | |
| kritična temperatura | |
| Trojna točka | |
| appearance | |
| barva | Črna | 
| appearance | silver-colored | 
| Lomni količnik | |
| thermodynamic material property | |
| Toplotna prevodnost | |
| thermal expansion | |
| molar heat capacity | |
| Toplotna kapaciteta | |
| Adiabatni eksponent | |
| electrical properties | |
| type | |
| Električna prevodnost | |
| Specifična upornost | |
| Superprevodnost | |
| Magnetizem | |
| type | |
| magnetic susceptibility (Mass) | |
| magnetic susceptibility (Molar) | |
| magnetic susceptibility (Volume) | |
| magnetic ordering | |
| Curiejeva temperatura | |
| Néelova temperatura | |
| struktura | |
| Kristalna struktura | {ERROR} | 
| lattice constant | |
| Lattice Angles | |
| mechanical property | |
| Trdota | |
| Stisljivostni modul | |
| Strižni modul | |
| Young's modulus | |
| Poissonovo število | |
| hitrost zvoka | |
| klasifikacija | |
| Kategorija | Aktinoidi, Actinides | 
| CAS Group | |
| IUPAC Group | |
| Glawe Number | 43 | 
| Mendeleev Number | 34 | 
| Pettifor Number | 38 | 
| Geochemical Class | |
| Goldschmidtovo razvrščanje elementov | synthetic | 
| Gas Basicity | |
|---|---|
| Polarizabilnost | |
| C6 Dispersion Coefficient | |
| allotrope | |
| Neutron cross section | 160  | 
| Neutron Mass Absorption | |
| Kvantno število | 5I15/2 | 
| Prostorska skupina | () | 
| Stable Isotopes | 0 | 
|---|---|
| Unstable Isotopes | 20 | 
| Natural Isotopes | 0 | 
| Masno število | 239 | 
|---|---|
| nevtronsko število | 140 | 
| Relative Atomic Mass | |
| g-factor | |
| natural abundance | |
| radioaktivnost | ☢️ radioactive element | 
| Razpolovni čas | |
| Spin | 3/2 | 
| nuclear quadrupole moment | |
| datum odkritja | |
| Parnost | - | 
| decay mode | Jakost | 
|---|---|
| α (α emission) | |
| β+ (β+ decay; β+ = ϵ + e+) | |
| SF (spontaneous fission) | 
| Masno število | 240 | 
|---|---|
| nevtronsko število | 141 | 
| Relative Atomic Mass | |
| g-factor | |
| natural abundance | |
| radioaktivnost | ☢️ radioactive element | 
| Razpolovni čas | 6 ± 1,7 s | 
| Spin | 4 | 
| nuclear quadrupole moment | |
| datum odkritja | 2017 | 
| Parnost | - | 
| decay mode | Jakost | 
|---|---|
| α (α emission) | 70% | 
| β+ (β+ decay; β+ = ϵ + e+) | 30% | 
| β+ SF (β+-delayed fission) | 0.16% | 
| Masno število | 241 | 
|---|---|
| nevtronsko število | 142 | 
| Relative Atomic Mass | |
| g-factor | |
| natural abundance | |
| radioaktivnost | ☢️ radioactive element | 
| Razpolovni čas | 5,1 ± 0,8 s | 
| Spin | 3/2 | 
| nuclear quadrupole moment | |
| datum odkritja | 1996 | 
| Parnost | - | 
| decay mode | Jakost | 
|---|---|
| α (α emission) | 100% | 
| β+ (β+ decay; β+ = ϵ + e+) | 
| Masno število | 242 | 
|---|---|
| nevtronsko število | 143 | 
| Relative Atomic Mass | |
| g-factor | |
| natural abundance | |
| radioaktivnost | ☢️ radioactive element | 
| Razpolovni čas | 17,8 ± 1,6 s | 
| Spin | 2 | 
| nuclear quadrupole moment | |
| datum odkritja | 1994 | 
| Parnost | + | 
| decay mode | Jakost | 
|---|---|
| α (α emission) | 57% | 
| β+ (β+ decay; β+ = ϵ + e+) | 43% | 
| β+ SF (β+-delayed fission) | 0.6% | 
| Masno število | 243 | 
|---|---|
| nevtronsko število | 144 | 
| Relative Atomic Mass | |
| g-factor | |
| natural abundance | |
| radioaktivnost | ☢️ radioactive element | 
| Razpolovni čas | 22,1 ± 1,4 s | 
| Spin | 7/2 | 
| nuclear quadrupole moment | |
| datum odkritja | 1973 | 
| Parnost | + | 
| decay mode | Jakost | 
|---|---|
| α (α emission) | 61% | 
| β+ (β+ decay; β+ = ϵ + e+) | |
| SF (spontaneous fission) | 1% | 
| Masno število | 244 | 
|---|---|
| nevtronsko število | 145 | 
| Relative Atomic Mass | |
| g-factor | |
| natural abundance | |
| radioaktivnost | ☢️ radioactive element | 
| Razpolovni čas | 37 ± 4 s | 
| Spin | 6 | 
| nuclear quadrupole moment | |
| datum odkritja | 1973 | 
| Parnost | + | 
| decay mode | Jakost | 
|---|---|
| β+ (β+ decay; β+ = ϵ + e+) | 95% | 
| α (α emission) | 5% | 
| β+ SF (β+-delayed fission) | 0.011% | 
| Masno število | 245 | 
|---|---|
| nevtronsko število | 146 | 
| Relative Atomic Mass | |
| g-factor | |
| natural abundance | |
| radioaktivnost | ☢️ radioactive element | 
| Razpolovni čas | 1,11 ± 0,06 m | 
| Spin | 3/2 | 
| nuclear quadrupole moment | |
| datum odkritja | 1967 | 
| Parnost | - | 
| decay mode | Jakost | 
|---|---|
| β+ (β+ decay; β+ = ϵ + e+) | 51% | 
| α (α emission) | 49% | 
| Masno število | 246 | 
|---|---|
| nevtronsko število | 147 | 
| Relative Atomic Mass | |
| g-factor | |
| natural abundance | |
| radioaktivnost | ☢️ radioactive element | 
| Razpolovni čas | 7,5 ± 0,5 m | 
| Spin | 4 | 
| nuclear quadrupole moment | |
| datum odkritja | 1954 | 
| Parnost | - | 
| decay mode | Jakost | 
|---|---|
| β+ (β+ decay; β+ = ϵ + e+) | 90.1% | 
| α (α emission) | 9.9% | 
| β+ SF (β+-delayed fission) | 0.003% | 
| Masno število | 247 | 
|---|---|
| nevtronsko število | 148 | 
| Relative Atomic Mass | |
| g-factor | |
| natural abundance | |
| radioaktivnost | ☢️ radioactive element | 
| Razpolovni čas | 4,55 ± 0,26 m | 
| Spin | 7/2 | 
| nuclear quadrupole moment | |
| datum odkritja | 1967 | 
| Parnost | + | 
| decay mode | Jakost | 
|---|---|
| β+ (β+ decay; β+ = ϵ + e+) | 93% | 
| α (α emission) | 7% | 
| SF (spontaneous fission) | 
| Masno število | 248 | 
|---|---|
| nevtronsko število | 149 | 
| Relative Atomic Mass | |
| g-factor | |
| natural abundance | |
| radioaktivnost | ☢️ radioactive element | 
| Razpolovni čas | 24 ± 3 m | 
| Spin | 2 | 
| nuclear quadrupole moment | |
| datum odkritja | 1956 | 
| Parnost | - | 
| decay mode | Jakost | 
|---|---|
| β+ (β+ decay; β+ = ϵ + e+) | 100% | 
| α (α emission) | 0.25% | 
| β+ SF (β+-delayed fission) | 3.5% | 
| Masno število | 249 | 
|---|---|
| nevtronsko število | 150 | 
| Relative Atomic Mass | |
| g-factor | |
| natural abundance | |
| radioaktivnost | ☢️ radioactive element | 
| Razpolovni čas | 102,2 ± 0,6 m | 
| Spin | 7/2 | 
| nuclear quadrupole moment | |
| datum odkritja | 1956 | 
| Parnost | + | 
| decay mode | Jakost | 
|---|---|
| β+ (β+ decay; β+ = ϵ + e+) | 100% | 
| α (α emission) | 0.57% | 
| Masno število | 250 | 
|---|---|
| nevtronsko število | 151 | 
| Relative Atomic Mass | |
| g-factor | |
| natural abundance | |
| radioaktivnost | ☢️ radioactive element | 
| Razpolovni čas | 8,6 ± 0,1 h | 
| Spin | 6 | 
| nuclear quadrupole moment | |
| datum odkritja | 1956 | 
| Parnost | 
| decay mode | Jakost | 
|---|---|
| β+ (β+ decay; β+ = ϵ + e+) | 100% | 
| α (α emission) | 
| Masno število | 251 | 
|---|---|
| nevtronsko število | 152 | 
| Relative Atomic Mass | |
| g-factor | |
| natural abundance | |
| radioaktivnost | ☢️ radioactive element | 
| Razpolovni čas | 33 ± 1 h | 
| Spin | 3/2 | 
| nuclear quadrupole moment | |
| datum odkritja | 1956 | 
| Parnost | - | 
| decay mode | Jakost | 
|---|---|
| ϵ (electron capture) | 99.5% | 
| α (α emission) | 0.5% | 
| Masno število | 252 | 
|---|---|
| nevtronsko število | 153 | 
| Relative Atomic Mass | |
| g-factor | |
| natural abundance | |
| radioaktivnost | ☢️ radioactive element | 
| Razpolovni čas | 471,7 ± 1,9 d | 
| Spin | 4 | 
| nuclear quadrupole moment | |
| datum odkritja | 1956 | 
| Parnost | + | 
| decay mode | Jakost | 
|---|---|
| α (α emission) | 78% | 
| ϵ (electron capture) | 22% | 
| Masno število | 253 | 
|---|---|
| nevtronsko število | 154 | 
| Relative Atomic Mass | |
| g-factor | 1,1714285714286 ± 0,02  | 
| natural abundance | |
| radioaktivnost | ☢️ radioactive element | 
| Razpolovni čas | 20,47 ± 0,03 d | 
| Spin | 7/2 | 
| nuclear quadrupole moment | 6,7 ± 0,8  | 
| datum odkritja | 1954 | 
| Parnost | + | 
| decay mode | Jakost | 
|---|---|
| α (α emission) | 100% | 
| SF (spontaneous fission) | 8.7% | 
| Masno število | 254 | 
|---|---|
| nevtronsko število | 155 | 
| Relative Atomic Mass | |
| g-factor | |
| natural abundance | |
| radioaktivnost | ☢️ radioactive element | 
| Razpolovni čas | 275,7 ± 0,5 d | 
| Spin | 7 | 
| nuclear quadrupole moment | |
| datum odkritja | 1954 | 
| Parnost | + | 
| decay mode | Jakost | 
|---|---|
| α (α emission) | 100% | 
| ϵ (electron capture) | |
| β− (β− decay) | 1.74% | 
| SF (spontaneous fission) | 3% | 
| Masno število | 255 | 
|---|---|
| nevtronsko število | 156 | 
| Relative Atomic Mass | |
| g-factor | |
| natural abundance | |
| radioaktivnost | ☢️ radioactive element | 
| Razpolovni čas | 39,8 ± 1,2 d | 
| Spin | 7/2 | 
| nuclear quadrupole moment | |
| datum odkritja | 1954 | 
| Parnost | + | 
| decay mode | Jakost | 
|---|---|
| β− (β− decay) | 92% | 
| α (α emission) | 8% | 
| SF (spontaneous fission) | 0.0041% | 
| Masno število | 256 | 
|---|---|
| nevtronsko število | 157 | 
| Relative Atomic Mass | |
| g-factor | |
| natural abundance | |
| radioaktivnost | ☢️ radioactive element | 
| Razpolovni čas | 7,6 h | 
| Spin | 7 | 
| nuclear quadrupole moment | |
| datum odkritja | 1976 | 
| Parnost | + | 
| decay mode | Jakost | 
|---|---|
| β− (β− decay) | 100% | 
| β− SF (β−-delayed fission) | 0.002% | 
| Masno število | 257 | 
|---|---|
| nevtronsko število | 158 | 
| Relative Atomic Mass | |
| g-factor | |
| natural abundance | |
| radioaktivnost | ☢️ radioactive element | 
| Razpolovni čas | 7,7 ± 0,2 d | 
| Spin | 7/2 | 
| nuclear quadrupole moment | |
| datum odkritja | 1987 | 
| Parnost | + | 
| decay mode | Jakost | 
|---|---|
| β− (β− decay) | 100% | 
| α (α emission) | 
| Masno število | 258 | 
|---|---|
| nevtronsko število | 159 | 
| Relative Atomic Mass | |
| g-factor | |
| natural abundance | |
| radioaktivnost | ☢️ radioactive element | 
| Razpolovni čas | |
| Spin | |
| nuclear quadrupole moment | |
| datum odkritja | |
| Parnost | 
| decay mode | Jakost | 
|---|---|
| β− (β− decay) | |
| α (α emission) | 

| odkritelj ali izumitelj | Argonne, Los Alamos, U of Calif | 
|---|---|
| nahajališče | United States | 
| datum odkritja | 1952 | 
| etimologija | Named in honor of the scientist Albert Einstein. | 
| pronunciation | ine-STINE-i-em (angleščina) | 
| Výskyt | |
|---|---|
| Abundance in Earth's crust | |
| natural abundance (ocean) | |
| natural abundance (človeško telo) | 0 % | 
| natural abundance (Meteoroid) | 0 % | 
| natural abundance (Sonce) | 0 % | 
| Abundance in Universe | 0 % |