Technetium

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

Property	Value
Atomic Number	43
Element	Technetium
Symbol	Tc
Atomic Mass	[98] (most stable isotope)
Number of Neutrons	55 (Technetium-98)
Number of Protons	43
Number of Electrons	43
Period	5
Group	7
Phase	Solid
Radioactive	Yes
Natural	No (primarily synthetic; trace amounts occur naturally)
Metal	Yes
Nonmetal	No
Metalloid	No
Type	Transition Metal
Atomic Radius	183 pm
Electronegativity	1.90 (Pauling scale)
First Ionization Energy	7.280 eV
Density	11.0 g/cm³
Melting Point	2157 °C
Boiling Point	4265 °C
Number of Isotopes	No stable isotopes (Tc-98, Tc-99 are most notable)
Discoverer	Carlo Perrier, Emilio Segrè
Year	1937
Specific Heat	0.243 J/g·K (estimated)
Number of Shells	5
Number of Valence Electrons	7