Groups ionization energies

As the atomic radius increases from top to bottom in a group, the valence electrons become more further away from the nucleus and the nuclear attraction forces on these electrons decrease. Therefore, as the atomic radius increases, the amount of energy required to remove an electron decreases. As a result, we can say that within a group ionization energy of elements decrease from top to bottom. 

Metallic character and ionic radii decrease across a period and down a group. Ionization energy increases across a period and decreases down a group. Large atoms typically have low ionization energies and are more metallic in character. 

Table 5.1 lists some of the atomic properties of the Group 2 elements. Comparison with the data for Group 1 elements (p. 75) shows the substantial increase in the ionization energies this is related to their smaller size and higher nuclear charge, and is particularly notable for Be. Indeed, the ionic radius of Be is purely a notional figure since no compounds are known in which uncoordinated Be has a 2- - charge. In aqueous solutions the reduction potential of... 

In its ground state, the free atom Si has the electronic configuration [Ne]3s 3p. Ionization energies and other properties are compared with those of the other members of Group 14 on p. 372. Silicon crystallizes in the diamond... 

The atomic properties of Ge, Sn and Pb are compared with those of C and Si in Table 10,1, Trends noted in previous groups are again apparent. The pairwise similarity in the ionization energies of Si and Ge (which can be related to the filling of the Sd shell) and of Sn and Pb... 

Figure 10.1 Suecessive ionization energies for Group 14 elements showing the influence of the Sd shell between Si and Ge and the 4f shell between Sn and Pb.

The stability of the electronic configuration is indicated by the fact that each element has the highest ionization energy in its period, though the value decreases down the group as a result of increasing size of the atoms. For the heavier elements is it actually smaller than for first-row elements such as O and F with consequences for the chemical reactivities of the noble gases which will be considered in the next section. Nuclear properties, particularly for xenon, have been exploited for nmr spectroscopy and Mdssbauer... 

Ionization energies of the main-group elements are listed in Figure 6.15. Notice that ionization energy—... 

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