Hafnium electronic configuration

Indicate the position of titanium, zirconium, and hafnium in Mendeleev s periodic table of the elements, the electron configurations and size of their atoms, and their oxidation states. 

Due to its 5t/-6.v- electron configuration, hafnium forms tctravalent compounds readily, although the Ilf1 ion docs not exist as such In aqueous solution except at very low pH values, Ihe common cation being HfO lor Hf OH)i ) and many of the tctravalent compounds are partly covalent. There are also less stable Hf(lll) compounds, There is close similarity in chemical properties to those of zirconium due to the similar outer electron configuration (4identical ionic radii (ZrJ is 0.80 A) the relatively low value for Hf being due lo the Lanthanide contraction. 

For practical purposes, then, the third transition series begins with hafnium, having the ground state outer electron configuration 6s25d2, and embraces the elements Ta, W, Re, Os, Ir, Pt, and Au, all of which have partially filled 5d shells in one or more chemically important oxidation states as well as (except Au) in the neutral atom. 

Give the electron configurations for sulfur (S), cadmium (Cd), hafnium (Hf), and radium (Ra), using the periodic table inside the front cover of this book. 

The Gp. IVA transition elements, titanium, zirconium and hafnium all have the [n — l)d2ws electron configuration. They differ from the transition elements of the later groups in their tendency to form compounds to the exclusion of those in which lower charge numbers occur especially is this true of Zr and Hf. 

Hafnium is element 72 and is found in Period 6, as shown in Figure 11.25. Note that it occurs just after the lanthanide series (see Figure 11.23). Thus the 4f orbitals are already filled. Hafnium is the second member of the Sd transition series and has two 5d electrons. Its electron configuration is... 

Thus the 4f orbitals are already filled. Hafnium is the second member of the 5d transition series and has two 5d electrons. Its electron configuration is... 

Table 2.3 Electronic configurations of atoms from hafnium to rutheifordium...

Hahnium (Ha) is expected to have the valence-electron configuration 7s 6d and thus to be a homolog of tantalum (with the valence electron configuration 6s 5d ). Zvara etal. (1976) have carried out a set of thermochromatography experiments similar to those done with rutherfordium. The isotope used for the study was the 1.8-s Ha produced in the Am( Ne, 4n) reaction, with detection by observation of its decay by spontaneous fission. The results of the experiments show the volatility of the chlorides and bromides of hahnium to be less than that of niobium (a 4d element which has the same deposition temperature in the chromatographic apparatus as tantalum) but relatively similar to that of hafnium. Gaggeler etaL (1992) and Tiirler et al. (1992), using the isotopes Ha (half-fives 34 s and 27 s), similarly find that the... 

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