Holmium

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

Property	Value
Atomic Number	67
Element	Holmium
Symbol	Ho
Atomic Mass	164.930 u
Number of Neutrons	98 (most common isotope, Holmium-165)
Number of Protons	67
Number of Electrons	67
Period	6
Group	Lanthanide (no fixed group number)
Phase	Solid
Radioactive	No
Natural	Yes
Metal	Yes
Nonmetal	No
Metalloid	No
Type	Lanthanide
Atomic Radius	226 pm
Electronegativity	1.23 (Pauling scale)
First Ionization Energy	6.022 eV
Density	8.80 g/cm³
Melting Point	1474 °C
Boiling Point	2700 °C
Number of Isotopes	1 stable (Holmium-165)
Discoverer	Marc Delafontaine, Jacques-Louis Soret
Year	1878
Specific Heat	0.165 J/g·K
Number of Shells	6
Number of Valence Electrons	3