103
Lr
266
Lawrencium (Lr)
Element 103 · Period 7 · Actinide series
actinide
solid at room temp
f-block
radioactive
synthetic
About Lawrencium
Last actinoid. Named after cyclotron inventor. Half-life about 11 hours.
Physical Properties
Atomic Mass
266 u
State at 25°C
Solid
Melting Point
1627 °C
Magnetism
Paramagnetic
Atomic Properties
Electron Configuration
[Rn] 5f¹⁴ 7s² 7p¹
Electron Shells
2, 8, 18, 32, 32, 8, 3
Electronegativity
1.3
Atomic Radius
246 pm
Ionization Energy
479 kJ/mol
Oxidation States
+3
Discovery & History
Discovered By
Albert Ghiorso
Discovery Year
1961
Named By
Albert Ghiorso
Name origin: Ernest Lawrence (cyclotron inventor)
Frequently Asked Questions
- Is Lawrencium a metal, nonmetal, or metalloid?
- Lawrencium is classified as a actinide.
- What state is Lawrencium in at room temperature?
- Lawrencium is a solid at standard room temperature (25°C).
- What is the atomic mass of Lawrencium?
- Lawrencium has an atomic mass of 266 atomic mass units (u).
- Who discovered Lawrencium?
- Lawrencium was discovered by Albert Ghiorso in 1961.
- Where is Lawrencium on the periodic table?
- Lawrencium is element number 103, located in period 7, part of the actinide series shown below the main table.