Bismuth ionization energy

Arrange the following atoms in order of increasing first ionization energy nitrogen, arsenic, bismuth. 

Element 115. A most intriguing situation is offered by element 115 (eka-bismuth) because a 7 3/2 electron is added here outside the 7/>i/2 closed shell. As pointed out by Fricke and Waher (85), the 7/>3/2 binding energy is much less than that of the Ipy electrons. Consequently, they predict that element 115 will have +1 as its normal oxidation state. Keller, Fricke and Nestor (99) have recently obtained prehminary results indicating that the +1 state will act like T1+. This prediction is based on the values they have obtained for the ionization energy. 

Phosphorus, Arsenic, Antimony and Bismuth Ligands Table 14 Gas Phase Ionization Energies of Phosphines... 

Comment on reasons for the trend in the first five ionization energies for bismuth (703,1610,2466,4370 and 5400kJ moP ). 

The two electrons in the low-energy s, orbital (with j - A and with m. values of + / and -A) arerelativistically stabilized with respect to the p levels, and form the inert pair typical of the chemistry of the 6p elements. In thallium the single 6p electron is in the p j orbital and to achieve trivalency a promotion of one of the 6s electrons to the relatively higher energy pjp orbital is necessaiy. In the lead atom, the two 6s electrons occupy the s,p orbital. The Pjy orbital is doubly occupied in lead and in bismuth. The single occupation of the destabilized p, orbital in bismuth explains the observation that the first ionization energy of the element (703 kJ mol ) is lower than that of lead (715 kJ mol ). 

Q16 Which one of the following represents the third ionization energy of bismuth (Bi) ... 

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