Lawrencium
actinide · period 7 · group 3 · d-block
Lawrencium is a synthetic chemical element with the symbol Lr (formerly Lw) and atomic number 103. It is named in honor of Ernest Lawrence, inventor of the cyclotron, a device that was used to discover many artificial radioactive elements.
What the numbers say
At standard temperature and pressure Lawrencium is a solid, sitting in period 7, group 3 of the d-block.
Its melting point of 1900 K (1627 °C) is the 22nd highest of the 110 elements with a measured value — mid-range among the elements.
Pauling electronegativity is 1.3. Paired with oxygen (3.44) that is a difference of 2.14, which puts the bond predominantly ionic — expect a stable oxide ceramic.
First identified in 1961.
Check it against computed structures
The structure search queries the Materials Project, OQMD and the Open Materials Database for computed crystal structures containing Lr — with DFT formation energy, hull stability and band gap where the provider publishes them.
K 2 · L 8 · M 18 · N 32 · O 32 · P 8 · Q 3
Properties
| Atomic number | 103 |
|---|---|
| Atomic mass | 266 u |
| Series | actinide |
| Group | 3 |
| Period | 7 |
| Block | d-block |
| Phase at STP | Solid |
| Melting point | 1900 K (1627 °C) |
| Electronegativity (Pauling) | 1.3 |
| Electron configuration | [Rn] 5f¹⁴ 7s² 7p¹ |
| Oxidation states | 3 |
| Discovered | 1961 |
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See Lr in context with all 118 elements.
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