Hafnium

Koushik 26/06/2026 19:58:08 Updated 26/06/2026 19:58:08

Property	Value
Atomic Number	72
Element	Hafnium
Symbol	Hf
Atomic Mass	178.49 u
Number of Neutrons	106 (most common isotope, Hafnium-178)
Number of Protons	72
Number of Electrons	72
Period	6
Group	4
Phase	Solid
Radioactive	No
Natural	Yes
Metal	Yes
Nonmetal	No
Metalloid	No
Type	Transition Metal
Atomic Radius	208 pm
Electronegativity	1.30 (Pauling scale)
First Ionization Energy	6.825 eV
Density	13.31 g/cm³
Melting Point	2233 °C
Boiling Point	4603 °C
Number of Isotopes	6 naturally occurring (Hf-174, Hf-176, Hf-177, Hf-178, Hf-179, Hf-180)
Discoverer	Dirk Coster, George de Hevesy
Year	1923
Specific Heat	0.144 J/g·K
Number of Shells	6
Number of Valence Electrons	4