Problem 7
The atomic and ionic radii of the first three group \(6 \mathrm{~A}\) elements are (a) Explain why the atomic radius increases in moving downward in the group. (b) Explain why the ionic radii are larger than the atomic radii. (c) Which of the three anjons would you expect to be the strongest base in water? Explain.
Problem 10
(a) Draw the Lewis structures for at least four species that have the general formula $$ [: \mathrm{X} \equiv \mathrm{Y}:]^{n} $$ where \(X\) and Y may be the same or different, and \(n\) may have a value from \(+1\) to \(-2 .(\mathrm{b})\) Which of the compounds is likely to be the strongest Brønsted base? Explain.
Problem 11
Identify each of the following elements as a metal, nonmetal, or metalloid: (a) phosphorus, (b) strontium, (c) manganese, (d) selenium, (e) rhodium, (f) krypton.
Problem 12
Identify each of the following elements as a metal, nonmetal, or metalloid: (a) gallium, (b) molybdenum, (c) tellurium, (d) arsenic, (e) xenon, (f) cadmium.
Problem 13
Consider the elements \(\mathrm{O}, \mathrm{Ba}, \mathrm{Co}, \mathrm{Be}, \mathrm{Br}\), and Se. From this list select the element that (a) is most electronegative, (b) exhibits a maximum oxidation state of \(+7\), (c) loses an electron most readily, (d) forms \(\pi\) bonds most readily, (e) is a transition metal.
Problem 15
Explain the following observations: (a) The highest fluoride compound formed by nitrogen is \(\mathrm{NF}_{y}\) whereas phosphorus readily forms \(\mathrm{PF}_{5}\). (b) Although \(\mathrm{CO}\) is a well-known compound, SiO does not exist under ordinary conditions. (c) \(\mathrm{AsH}_{3}\) is a stronger reducing agent than \(\mathrm{NH}_{3}\).
Problem 16
Explain the following observations: (a) \(\mathrm{HNO}_{3}\) is a stronger oxidizing agent than \(\mathrm{H}_{3} \mathrm{PO}_{4} .\) (b) Silicon can form an ion with six fluorine atoms, \(\mathrm{SiF}_{6}^{2-}\), whereas carbon is able to bond to a maximum of four, \(\mathrm{CF}_{4}\) (c) There are three compounds formed by carbon and hydrogen that contain two carbon atoms each \(\left(\mathrm{C}_{2} \mathrm{H}_{2}, \mathrm{C}_{2} \mathrm{H}_{4}\right.\), and \(\left.\mathrm{C}_{2} \mathrm{H}_{6}\right)\), whereas sili- con forms only one analogous compound \(\left(\mathrm{Si}_{2} \mathrm{H}_{6}\right)\).
Problem 17
Complete and balance the following equations: (a) \(\mathrm{Mg}_{3} \mathrm{~N}_{2}(\mathrm{~s})+\mathrm{H}_{2} \mathrm{O}(l) \longrightarrow\) (b) \(\mathrm{C}_{3} \mathrm{H}_{7} \mathrm{OH}(l)+\mathrm{O}_{2}(g) \longrightarrow\) (c) \(\mathrm{MnO}_{2}(s)+\mathrm{C}(s) \stackrel{\Delta}{\longrightarrow}\) (d) \(\mathrm{AlP}(s)+\mathrm{H}_{2} \mathrm{O}(I) \longrightarrow\) (e) \(\mathrm{Na}_{2} \mathrm{~S}(\mathrm{~s})+\mathrm{HCl}(a q) \longrightarrow\)
Problem 18
Complete and balance the following equations: (a) \(\mathrm{NaOCH}_{3}(\mathrm{~s})+\mathrm{H}_{2} \mathrm{O}(l) \longrightarrow\) (b) \(\mathrm{CuO}(\mathrm{s})+\mathrm{HNO}_{3}(a q) \longrightarrow\) (c) \(\mathrm{WO}_{3}(\mathrm{~s})+\mathrm{H}_{2}(g) \stackrel{\Delta}{\longrightarrow}\) (d) \(\mathrm{NH}_{2} \mathrm{OH}(l)+\mathrm{O}_{2}(g) \longrightarrow\) (e) \(\mathrm{Al}_{4} \mathrm{C}_{3}(\mathrm{~s})+\mathrm{H}_{2} \mathrm{O}(l) \longrightarrow\)
Problem 19
(a) Give the names and chemical symbols for the three isotopes of hydrogen. (b) List the isotopes in order of decreasing natural abundance.
