103Lr266.000
Actinided-blockRadioactive
Lawrencium
Element 103 on the periodic table, symbol Lr, group 3, period 7.
Lawrencium is a synthetic chemical element with chemical 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. A radioactive metal, lawrencium is the eleventh transuranic element and is also the final member of the actinide series.
Properties
- Atomic Number
- 103
- Atomic Mass
- 266.0000 u
- Group
- 3
- Period
- 7
- Block
- d-block
- Category
- Actinide
- State at 25 °C
- Solid
- Melting Point
- 1,900 K · 1,626.9 °C
- Boiling Point
- Not measured
- Density
- Not measured
- Atomic Radius
- Not measured
- Electronegativity
- 1.3
- Oxidation States
- +3
- Abundance in Crust
- Vanishingly rare
- Discovered
- 1961
- Discovered By
- Lawrence Berkeley National Laboratory
Electron Configuration
[Rn] 5f14 7s2 7p1
1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d10 6p6 7s2 5f14 7p1
Ionisation Energies (kJ/mol)
- 1. 470
Elements near Lawrencium
Elements in the same group share the number of outer electrons and behave in similar ways. Elements in the same period share a shell, so they change steadily from left to right.