Science, Tech, Math › Science Rhenium Facts (Re or Atomic Number 75) Chemical & Physical Properties of Rhenium Share Flipboard Email Print Malachy120 / Getty Images Science Chemistry Periodic Table Basics Chemical Laws Molecules Projects & Experiments Scientific Method Biochemistry Physical Chemistry Medical Chemistry Chemistry In Everyday Life Famous Chemists Activities for Kids Abbreviations & Acronyms Biology Physics Geology Astronomy Weather & Climate By Anne Marie Helmenstine, Ph.D. Chemistry Expert Ph.D., Biomedical Sciences, University of Tennessee at Knoxville B.A., Physics and Mathematics, Hastings College Dr. Helmenstine holds a Ph.D. in biomedical sciences and is a science writer, educator, and consultant. She has taught science courses at the high school, college, and graduate levels. our editorial process Facebook Facebook Twitter Twitter Anne Marie Helmenstine, Ph.D. Updated December 07, 2019 Rhenium is a heavy, silvery-white transition metal. It has element symbol Re and atomic number 75. The element's properties were predicted by Mendeleev when he designed his periodic table. Here is a collection of rhenium element facts. Rhenium Basic Facts Symbol: Re Atomic Number: 75 Atomic Weight: 186.207 Electron Configuration: [Xe] 4f14 5d5 6s2 Element Classification: Transition Metal Discovery: Walter Noddack, Ida Tacke, Otto Berg 1925 (Germany) Name Origin: Latin: Rhenus, the Rhine River. Uses: Rhenium is used to make high-temperature superalloys that are used in jet engines (70% of rhenium production). The element is also used to prepare platinum-rhenium catalysts used to make high-octane unleaded gasoline. The radioactive isotopes rhenium-188 and rhenium-186 are used to treat liver cancer and may be applicable to pancreatic cancer. Biological Role: Rhenium serves no known biological role. Because the elements and its compounds are used in small amounts, they have not been widely studied for toxicity. Two compounds studied in rats (rhenium trichloride and potassium perrhenate) displayed very low toxicity, comparable to that of table salt (sodium chloride). Rhenium Physical Data Density (g/cc): 21.02 Melting Point (K): 3453 Boiling Point (K): 5900 Appearance: dense, silvery-white metal Atomic Radius (pm): 137 Atomic Volume (cc/mol): 8.85 Covalent Radius (pm): 128 Ionic Radius: 53 (+7e) 72 (+4e) Specific Heat (@20°C J/g mol): 0.138 Fusion Heat (kJ/mol): 34 Evaporation Heat (kJ/mol): 704 Debye Temperature (K): 416.00 Pauling Negativity Number: 1.9 First Ionizing Energy (kJ/mol): 759.1 Oxidation States: 5, 4, 3, 2, -1 Lattice Structure: hexagonal Lattice Constant (Å): 2.760 Lattice C/A Ratio: 1.615 Sources Emsley, John (2011). Nature's building blocks: An A-Z Guide to the Elements. Oxford University Press. ISBN 978-0-19-960563-7.Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 978-0-08-037941-8.Hammond, C. R. (2004). The Elements, in Handbook of Chemistry and Physics (81st ed.). CRC press. ISBN 978-0-8493-0485-9.Scerri, Eric (2013). A Tale of Seven Elements. Oxford University Press. ISBN 978-0-19-539131-2.Weast, Robert (1984). CRC, Handbook of Chemistry and Physics. Boca Raton, Florida: Chemical Rubber Company Publishing. pp. E110. ISBN 0-8493-0464-4.