43Tc96.90636
Technetium
Transition Metal
Solid at STP
Period 5Group 7Block DDiscovered 1937
[Kr]5s2 4d5
Technetium (/tɛkˈniːʃiəm/) is a chemical element with symbol Tc and atomic number 43. It is the element with the lowest atomic number in the periodic table that has no stable isotopes:every form of it is radioactive. Nearly all technetium is produced synthetically, and only minute amounts are found in nature.
📖 Read more on Wikipedia →Atomic Properties
| Atomic Number | 43 |
| Atomic Mass | 96.90636 u |
| Electron Configuration | [Kr]5s2 4d5 |
| Oxidation States | +7, +6, +4 |
| Electronegativity | 1.9 (Pauling) |
| Atomic Radius | 209 pm |
| Ionization Energy | 7.28 eV |
| Electron Affinity | 0.55 eV |
| Block | D |
Physical Properties
| Appearance | shiny gray metal |
| Standard State | Solid |
| Melting Point | 2430 K (2156.8 °C) |
| Boiling Point | 4538 K (4264.9 °C) |
| Density | 11 g/cm³ |
| Molar Heat | 24.27 J/(mol·K) |
| CPK Color | #3B9E9E |
Classification
| Category | Transition Metal |
| Group Block | Transition metal |
| Period | 5 |
| Group | 7 |
| Block | D |
Discovery
| Year Discovered | 1937 |
| Discovered By | Emilio Segrè |
| Electron Shells | 2, 8, 18, 13, 2 |