Rutherfordium

Rutherfordium was the opening shot of the Transfermium Wars: Dubna claimed it in 1964 and proposed kurchatovium, Berkeley claimed it in 1969 and proposed rutherfordium, and the dispute over 104 through 109 ran for nearly thirty years before IUPAC's 1997 compromise settled every name at once. The chemistry mattered more than the name. Actinide theory predicted element 104 would be the first true d-block metal of period 7, and gas-phase experiments on single atoms showed its chloride and bromide are volatile like zirconium's and hafnium's, not like the non-volatile actinide halides — the direct confirmation that Seaborg's actinide concept ended where he said it did. Its longest-lived isotope survives about 80 minutes.