Nobelium

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

Property	Value
Atomic Number	102
Element	Nobelium
Symbol	No
Atomic Mass	[259] (most stable isotope)
Number of Neutrons	157 (Nobelium-259)
Number of Protons	102
Number of Electrons	102
Period	7
Group	Actinide (no fixed group number)
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	6.65 eV (estimated)
Density	~9.9 g/cm³ (estimated)
Melting Point	827 °C (estimated)
Boiling Point	— (not well established)
Number of Isotopes	No stable isotopes (No-259 most notable)
Discoverer	Joint Institute for Nuclear Research (Dubna) and Lawrence Berkeley National Laboratory
Year	1957
Specific Heat	— (not well established)
Number of Shells	7
Number of Valence Electrons	2