Silver metal. Protected silver has greater optical reflectivity than aluminium at all wavelengths longer than ~450 nm. At wavelengths shorter than 450 nm, silver's reflectivity is inferior to that of aluminium and drops to zero near 310 nm. Very high electrical and thermal conductivity is common to the elements in group 11, because their single s electron is free and does not interact with the filled d subshell, as such interactions (which occur in the preceding transition metals) lower electron mobility. The electrical conductivity of silver is the greatest of all metals, greater even than copper, but it is not widely
Metallic hydrogen metallized and become superconducting by M.I. Eremets "et al.". This claim is disputed, and their results have not been repeated. In 2011 Eremets and Troyan reported observing the liquid metallic state of hydrogen and deuterium at static pressures of . This claim was questioned by other researchers in 2012. In 2015, scientists at the Z Pulsed Power Facility announced the creation of metallic deuterium using dense liquid deuterium, an electrical insulator-to-conductor transition associated with an increase in optical reflectivity. On 5 October 2016, Ranga Dias and Isaac F. Silvera of Harvard University released claims of experimental evidence that solid metallic