Re
Rhenium is one of the rarest elements with the third-highest melting point.
Physical Properties
| Atomic Mass | 186.21 u |
| Density | 21.02 g/cm³ |
| Melting Point | 3459.0 K |
| Boiling Point | 5869.0 K |
| Appearance | Silvery-grayish metallic |
| State at Room Temp | Solid |
Chemical Properties
| Electronegativity | 1.9 (Pauling) |
| 1st Ionization Energy | 760.0 kJ/mol |
| Electron Affinity | 5.8 kJ/mol |
| Oxidation States | +1, +2, +3, +4, +5, +6, +7 |
Atomic Properties
| Electron Configuration | [Xe] 4f14 5d5 6s2 |
| Atomic Radius | 137.0 pm |
| Covalent Radius | 151.0 pm |
| Van der Waals Radius | 217.0 pm |
Discovery
| Discovered By | Masataka Ogawa, Walter Noddack, Ida Tacke, Otto Berg |
| Discovery Year | 1925 |
| Location | Germany |
| Named After | Latin 'Rhenus' meaning the Rhine River |
About Rhenium
Rhenium is a silvery-gray, heavy metal with the third-highest melting point. It was the last stable element to be discovered. The world's annual production is only about 50 tonnes.
Uses & Applications
Jet engine superalloys, petroleum refining catalysts, thermocouples, and mass spectrometer filaments.
Fun Fact
Rhenium was the last naturally occurring stable element discovered (1925) and only about 50 tonnes are produced per year worldwide.
Isotopes
| Mass Number | Abundance | Half-Life | Stable |
| 185 | 0.374% | - | Yes |
| 187 | 0.626% | 4.12e10 years | No |
Electron Configuration
[Xe] 4f14 5d5 6s2