Problem 1
Identify the groups of the periodic table to which the elements with the following general ground state electronic configurations belong: (a) \(n s^{2} n p^{4}\) (b) \(n s^{1}\) (c) \(n s^{2} n p^{6}\) (d) \(n s^{2}\) (e) \(n s^{2}(n-1) d^{10}\) (f) \(n s^{2} n p^{1}\)
Problem 2
An element, X, has the ground state electronic configuration \(1 s^{2} 2 s^{2} 2 p^{6} 3 s^{2} 3 p^{6} 4 s^{2} 3 d^{5}\) (a) How many valence electrons does X possess? (b) What is the atomic number of \(\mathrm{X} ?\) (c) To which block of elements does X belong? (d) To which group does X belong? (e) Is \(\mathrm{X}\) a metal, semi-metal or non-metal? (f) Write out the ground state electronic configuration of the element after \(\mathrm{X}\) in the periodic table.
Problem 3
An element, \(Z\), has the ground state electronic configuration \(1 s^{2} 2 s^{2} 2 p^{6} 3 s^{2} 3 p^{4}\) (a) How many valence electrons does \(Z\) possess? (b) To which block of elements does Z belong? (c) To which group does Z belong? (d) Does \(Z\) readily form a cation or anion? If so, suggest its formula. (e) Is \(\mathrm{Z}\) a metal, semi-metal or non-metal? (f) Write out the ground state electronic configuration of the element above \(\mathrm{Z}\) in the periodic table.
Problem 5
In terms of electronic configurations, why is He unique among the group 18 elements?
Problem 8
Write equations to define the processes to which \(\Delta_{\mathrm{a}} H^{\mathrm{o}}(298 \mathrm{K})\) refers for each of the following elements: (a) \(\mathrm{F} ;\) (b) \(\mathrm{Rb} ;(\mathrm{c}) \mathrm{Br}\) \(\mathrm{r} ;(\mathrm{d}) \mathrm{V} ;(\mathrm{e}) \mathrm{Si}\)
Problem 9
Values of the first five ionization energies of an element, A, are 737.7,1451,7733,10540 and \(13630 \mathrm{kJ} \mathrm{mol}^{-1} .\) Suggest (a) to which group A belongs, and (b) whether A is a metal or non-metal.
Problem 13
Rationalize why the metallic radii of the group 1 and 2 metals increase down each group.
Problem 17
How do you expect the van der Waals radii of the group 18 elements to vary down the group? Rationalize your answer.
Problem 21
Comment on the following values of \(r_{\text {ion }}\) for vanadium: $$\begin{array}{lll} \text { Oxidation state } & \text { Coordination number } & r_{\text {ion }} / \mathrm{pm} \\ +2 & 6 & 79 \\ +3 & 6 & 64 \\ +4 & 6 & 58 \\ +4 & 5 & 53 \\ +5 & 6 & 54 \\ +5 & 5 & 46 \end{array}$$
