Periodic TableLawrencium (Lr)
Lawrencium is an actinide with atomic number 103, in period 7 of the periodic table. Its atomic mass is 266 u and its electron configuration is [Rn] 5f¹⁴ 7s² 7p¹.
Key facts
| Atomic number | 103 |
|---|---|
| Atomic mass | 266 u |
| Category | Actinide |
| Period | 7 |
| Group | --- |
| Block | d |
| Electron configuration | [Rn] 5f¹⁴ 7s² 7p¹ |
| Electrons per shell | 2, 8, 18, 32, 32, 8, 3 |
| Electronegativity (Pauling) | 1.3 |
| Oxidation states | +3common in bold |
| State at 25 °C | --- |
| Melting point | 1900 K1626.85 °C |
| Boiling point | --- |
| Density | 14.4 g/cm³ |
Atomic properties
| First ionization energy | 4.96 eV |
|---|---|
| Electron affinity | --- |
| Atomic radius | --- |
| Covalent radius | --- |
| Van der Waals radius | --- |
| Common ions | Lr³⁺ |
| Protons, neutrons, electrons | 103, 163, 103 |
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 | Simple hexagonal |
| Magnetic type | --- |
Identification and history
| CAS number | 22537-19-5 |
|---|---|
| Latin name | Lawrencium |
| Discovered by | JINR, LLNL · 1961 |
| Named by | --- |
Natural isotopes
Lawrencium has no stable isotopes: every isotope is radioactive.
No visible amount of Lawrencium 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 Lawrencium in the app
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