Rhenium

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

Property	Value
Atomic Number	75
Element	Rhenium
Symbol	Re
Atomic Mass	186.207 u
Number of Neutrons	112 (most common isotope, Rhenium-187)
Number of Protons	75
Number of Electrons	75
Period	6
Group	7
Phase	Solid
Radioactive	No (Re-187 is very weakly radioactive)
Natural	Yes
Metal	Yes
Nonmetal	No
Metalloid	No
Type	Transition Metal
Atomic Radius	188 pm
Electronegativity	1.90 (Pauling scale)
First Ionization Energy	7.834 eV
Density	21.02 g/cm³
Melting Point	3186 °C
Boiling Point	5596 °C
Number of Isotopes	2 naturally occurring (Re-185, Re-187)
Discoverer	Walter Noddack, Ida Tacke, Otto Berg
Year	1925
Specific Heat	0.137 J/g·K
Number of Shells	6
Number of Valence Electrons	7