Periodic TableNobelium (No)
Nobelium is an actinide with atomic number 102, in period 7, in the f-block of the periodic table. Its atomic mass is 259 u and its electron configuration is [Rn] 5f¹⁴ 7s².
Key facts
| Atomic number | 102 |
|---|---|
| Atomic mass | 259 u |
| Category | Actinide |
| Period | 7 |
| Group | f-block, no group number |
| Block | f |
| Electron configuration | [Rn] 5f¹⁴ 7s² |
| Electrons per shell | 2, 8, 18, 32, 32, 8, 2 |
| Electronegativity (Pauling) | 1.3 |
| Oxidation states | +2, +3common in bold |
| State at 25 °C | --- |
| Melting point | 1100 K826.85 °C |
| Boiling point | --- |
| Density | 9.9 g/cm³ |
Atomic properties
| First ionization energy | 6.626 eV |
|---|---|
| Electron affinity | --- |
| Atomic radius | --- |
| Covalent radius | --- |
| Van der Waals radius | --- |
| Common ions | No²⁺, No³⁺ |
| Protons, neutrons, electrons | 102, 157, 102 |
Physical and thermal properties
| Molar volume | --- |
|---|---|
| Heat of fusion | --- |
| Heat of vaporization | --- |
| Specific heat | --- |
| Thermal conductivity | --- |
| Thermal expansion | --- |
| Mohs hardness | --- |
| Young’s modulus | --- |
| Crystal structure | Face-centered cubic |
| Magnetic type | --- |
Identification and history
| CAS number | 10028-14-5 |
|---|---|
| Latin name | Nobelium |
| Discovered by | Institute for Nuclear Research · 1966 |
| Named by | --- |
Natural isotopes
Nobelium has no stable isotopes: every isotope is radioactive.
No visible amount of Nobelium has ever been made: its physical properties here are theoretical estimates, not measurements.
Data checked against PubChem (NIH), IUPAC, the NIST Atomic Spectra Database and the IAEA (NUBASE and AME), the same data you see in the app.
A dash (---) means there is no reliable published measurement. The app never makes one up.
See Nobelium in the app
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