Lawrencium

Chaitra 26/06/2026 19:58:09 Updated 26/06/2026 19:58:09

Property	Value
Atomic Number	103
Element	Lawrencium
Symbol	Lr
Atomic Mass	[266] (most stable isotope)
Number of Neutrons	163 (Lawrencium-266)
Number of Protons	103
Number of Electrons	103
Period	7
Group	3 (sometimes classified with actinides)
Phase	Solid (predicted)
Radioactive	Yes
Natural	No (synthetic element)
Metal	Yes
Nonmetal	No
Metalloid	No
Type	Actinide
Atomic Radius	~190 pm (estimated)
Electronegativity	1.30 (estimated)
First Ionization Energy	4.96 eV (estimated)
Density	~14.4 g/cm³ (estimated)
Melting Point	~1627 °C (estimated)
Boiling Point	— (not well established)
Number of Isotopes	No stable isotopes (Lr-266 most notable)
Discoverer	Albert Ghiorso, Torbjørn Sikkeland, Almon E. Larsh, Robert M. Latimer
Year	1961
Specific Heat	— (not well established)
Number of Shells	7
Number of Valence Electrons	3