The following table lists experimental values for three atomic properties of five consecutive elements in Period 3 (elements are presented in no particular order).
Element
First ionization energy / kJmol−1
Electronegativity (Pauling)
Electron affinity / kJmol−1
A
496
0.93
–53
B
1000
2.16
–73
C
786
1.31
0
D
1251
2.58
–200
E
578
1.00
–48
(a) Arrange the five elements in the order in which they appear from left to right across Period 3 of the periodic table. Clearly state the reasoning behind your ordering.
(b) Describe the overall trend observed for each of the three properties as atomic number increases across the period. Comment explicitly on the correlation among the three trends.
(c) Identify the element in the series whose electron-affinity value differs markedly from the general trend you described in part (b). Provide a detailed explanation, in terms of electron configuration and effective nuclear charge, for why this deviation occurs.
a. Part (a)
b. Part (b)
c. Part (c)