Technetium (Tc)
Technetium (Tc) is element 43, a transition metal. Atomic mass 98, configuration [Kr] 4d⁵ 5s². Properties, isotopes, oxidation states, uses and history, with an interactive 3D atom model.
Key facts
| Atomic number | 43 |
|---|---|
| Symbol | Tc |
| Standard atomic weight | 98 |
| Category | Transition Metal |
| Group | 7 |
| Period | 5 |
| State at room temperature | Solid |
| Electron configuration | [Kr] 4d⁵ 5s² |
| Valence electrons | 2 (Variable) |
| Common oxidation states | +4, +7 |
| Common ions | No common ions |
| Electronegativity (Pauling) | 2.1 |
| First ionization energy | 702 kJ/mol |
| Electron affinity | 53.07 kJ/mol |
| Atomic radius | 183 pm |
| Density | 11 g/cm³ |
| Melting point | 2156°C |
| Boiling point | 4265°C |
Common uses
- Medical imaging (Bone scans, heart scans)
- Research
Where it matters
- Nuclear Medicine (Tc-99m is the world's most used medical radiotracer)
Hazards
- Radioactive (radiotoxicity depends on isotope)
History
| Discovered | 1937 |
|---|---|
| Discovered by | Carlo Perrier & Emilio Segrè |
| Name | From Greek technetos (artificial) |