91Ó°ÊÓ

Arrange the elements in each of the following sets in order of decreasing atomic radius: (a) bromine, chlorine, iodine; (b) gallium, selenium, arsenic; (c) calcium, potassium, zinc; (d) barium, calcium, strontium.

Place the following ions in order of increasing ionic radius: \(\mathrm{S}^{2-}, \mathrm{Cl}^{-}, \mathrm{P}^{3-}\).

Which ion of each of the following pairs has the larger radius: (a) \(\mathrm{Ca}^{2+}, \mathrm{Ba}^{2+} ;\) (b) \(\mathrm{As}^{3-}, \mathrm{Se}^{2-} ;\) (c) \(\mathrm{Sn}^{2+}, \mathrm{Sn}^{4+}\) ?

Which member of each pair has the smaller first ionization energy: (a) \(\mathrm{Ca}\) or \(\mathrm{Mg}\); (b) \(\mathrm{Mg}\) or \(\mathrm{Na}\); (c) \(\mathrm{Al}\) or \(\mathrm{Na}\) ?

Which member of each pair is likely to have the smaller second ionization energy: (a) \(\mathrm{Ca}\) or \(\mathrm{Mg}\); (b) \(\mathrm{Mg}\) or \(\mathrm{Na}\); (c) \(\mathrm{Al}\) or \(\mathrm{Na}\) ?

Place each of the following sets of elements in order of decreasing ionization energy. Explain your choices. (a) Selenium, oxygen, tellurium; (b) gold, tantalum, osmium; (c) lead, barium, cesium.

Which element of each of the following pairs has the higher electron affinity: (a) aluminum or indium; (b) bismuth or antimony; (c) silicon or lead?

(a) What is the inert-pair effect? (b) Why is the inert-pair effect observed only for heavy elements?

(a) What is a diagonal relationship? (b) How does it arise? (c) Give two examples to illustrate the concept.

Which of the following pairs of elements exhibit a diagonal relationship: (a) \(\mathrm{Li}\) and \(\mathrm{Mg}\); (b) \(\mathrm{Ca}\) and \(\mathrm{Al}\); (c) \(\mathrm{F}\) and S?