Roentgenium (Rg) is a synthetic, highly radioactive chemical element belonging to the category Transition metal, with atomic number 111 and atomic mass 282.0000 u (based on its most stable known isotope). This sheet describes its fundamental properties, position in the periodic table and physical characteristics.
Roentgenium (Rg)
Identity
- Name: Roentgenium
- Symbol: Rg
- Atomic number: 111
- Atomic mass: 282.0000 u
Position in the periodic table
- Group: 11
- Period: 7
- Category: Transition metal
Physico-chemical properties
- Standard state: Presumably solid (synthetic, not observed in bulk)
- Melting point: Unknown (predicted to be very high)
- Density: Unknown (probably very high)
- Electron configuration: [Rn] 5f¹⁴ 6d⁹ 7s² (predicted)
Scientific description
Roentgenium is a synthetic, highly radioactive chemical element with symbol Rg and atomic number 111. It belongs to the category of Transition metal and occupies group 11 and period 7 in the periodic table. No stable isotopes are known; the value 282.0000 u corresponds to the most stable known isotope. Because only a few atoms have ever been produced, its macroscopic physical properties such as melting point, density and crystal structure remain unknown and are estimated from theoretical calculations.