Niobium

Charles Hatchett examined a black mineral in the British Museum in 1801 that had been sent from Connecticut by John Winthrop, found a new element and called it columbium after the country it came from. Others then confused it with tantalum, which sits directly below it and behaves almost identically, and the muddle lasted a century and a half; IUPAC settled on niobium in 1949, but American metallurgical practice said columbium for decades afterwards and some still do. Niobium-titanium wire is the standard low-temperature superconductor, carrying the current in essentially every MRI magnet in the world and in the LHC's 1232 dipole magnets. Adding a few hundredths of a percent to steel refines the grain enough to raise strength substantially, which is why microalloyed niobium steel goes into pipelines and car bodies. Its ground state is the irregular 4d⁴ 5s¹.