The following properties of astatine have been measured or estimated: 

(a) Covalent radius; 

(b) Ionic radius (At^–);

(c) First ionization energy; 

(d) Electron affinity; 

(e) Electronegativity; 

(f) Standard reduction potential. 

Based on periodic relationships and data in Table 22.4, what values would you expect for these properties?

Table 22.4

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TABLE 22.4 Group 17 Elements: The Halogens Fluorine (F) Pale yellow gas -220 - 188 Physical form at room temperature Melting point, °C Boiling point, °C Electron configuration Covalent radius, pm Ionic (X) radius, pm First ionization energy, kJ mol-1 Electron affinity, kJ mol-¹ Electronegativity Standard electrode potential, V (X₂ + 2 e 2 X¯) [He]2s²2p5 71 133 1681 -328.0 4.0 2.866 Chlorine (CI) Yellow-green gas -101 -35 [Ne]3s²3p5 99 181 1251 -349.0 3.0 1.358 Bromine (Br) Dark red liquid -7.2 58.8 [Ar]3d¹04s²4p5 114 196 1140 -324.6 2.8 1.065 lodine (1) Violet-black solid 114 184 [Kr]4d¹05s25p5 133 220 1008 -295.2 2.5 0.535