Co-extracted with Zr and then split from it by solvent extraction of their thiocyanate complexes (Hf prefers the aqueous phase, Zr the organic); HfCl4 is reduced by the Kroll process.
Research Elements Hf · atomic number 72 Transition metal · period 6, group 4 [Xe] 4f14 5d2 6s2 Shells: 2, 8, 18, 32, 10, 2 Valence electrons: 2 in the outer shell (6s2), and 2 in 5d2 Green dots are the outer shell's s and p electrons. Softer green dots are the d electrons of transition metals, and the d and f electrons of lanthanides and actinides: they often take part in bonding, but not always. Grey dots are the core. Ground-state configuration from the NIST Atomic Spectra Database (A. Kramida, Yu. Ralchenko, J. Reader and the NIST ASD Team). Abundance is the mole fraction of the element found as that isotope on Earth; digits in parentheses are the uncertainty in the last digits. Masses and abundances from NIST, Atomic Weights and Isotopic Compositions (J. S. Coursey, D. J. Schwab, J. J. Tsai and R. A. Dragoset, National Institute of Standards and Technology).Hafnium
Electrons
How it's obtained
Natural isotopes
Isotope Relative atomic mass Abundance 174Hf 173.9400461(28) 0.0016(1) 176Hf 175.9414076(22) 0.0526(7) 177Hf 176.9432277(20) 0.1860(9) 178Hf 177.9437058(20) 0.2728(7) 179Hf 178.9458232(20) 0.1362(2) 180Hf 179.9465570(20) 0.3508(16)