Technetium - ASCII Periodic Table of the Elements

ASCII PERIODIC TABLE OF THE ELEMENTS

  Tc

Relative atomic mass: [98]

English: Technetium
French: Technetium
Croatian: Tehnecij
German: Technetium
Italian: Tecnezio
Spanish: Tecnecio

Atomic number: 43
Group numbers: 7
Period: 5
Standard state (20 ^oC): solid

Discovery: 1937 Carlo Perrier (IT), Emilio Segre (US)

Technetium was discovered by Carlo Perrier (IT) and Emilio Segre (US) in 1937. The origin of the name comes from the Greek word technikos meaning artificial. It is a silvery-grey metal that resists oxidation but tarnishes in moist air and burns in high oxygen environment. Technetium is the first synthetically produced element. It is also radioactive. Technetium is made by bombarding molybdenum with deuterons (heavy hydrogen) in a cyclotron. Added to iron in quantities as low as 55 part-per-million transforms the iron into a corrosion-resistant alloy.

Electronic configuration: [Kr] 4d⁶ 5s¹
Formal oxidation number: +4 +6 +7
Atomic radius: 135.2 pm

Electronegativities: 2.1
Thermal conductivity: 50.6 W/(m K)
Electrical resistivity (20 ^oC): 16.9 microOhm cm

Melting point: 2157 ^oC
Boiling point: 4265 ^oC

Heat of fusion: 23.81 kJ/mol
Heat of vaporization: 585.22 kJ/mol
Heat of atomization: 678 kJ/mol