Chapter 7

Write the electron configurations for \(P\) and \(C l\) using both spdf notation and orbital box diagrams. Describe the relationship between each atom's electron configuration and its position in the periodic table.

Write the electron configurations for \(\mathrm{Mg}\) and Ar using both spdf notation and orbital box diagrams. Describe the relationship of the atom's electron configuration to its position in the periodic table.

Using spdf notation, write the electron configurations for atoms of chromium and iron, two of the major components of stainless steel.

Using spdf notation, give the electron configuration of vanadium, \(V\), an element found in some brown and red algae and some toadstools.

Depict the electron configuration for each of the following atoms using spdf and noble gas notations. (a) Arsenic, As. A deficiency of As can impair growth in animals, but larger amounts are poisonous. (b) Krypton, Kr. It ranks seventh in abundance of the gases in Earth's atmosphere.

Use noble gas and spdf notations to depict electron configurations for the following metals of the third transition series. (a) Tantalum, Ta. The metal and its alloys resist corrosion and are often used in surgical and dental tools. (b) Platinum, Pt. This metal was used by pre-Columbian Indians in jewelry. Now it is still used in jewelry but it is also the basis for anticancer drugs and catalysts (such as those in automobile exhaust systems).

The lanthanides, once called the rare earth elements, are really only "medium rare." Using noble gas and spdf notations, depict reasonable electron configurations for the following elements. (a) Samarium, Sm. This lanthanide is used in magnetic materials. (b) Ytterbium, Yb. This element was named for the village of Ytterby in Sweden, where a mineral source of the element was found.

The actinide americium, Am, is a radioactive element that has found use in home smoke detectors. Depict its electron configuration using noble gas and spdf notations.

Predict electron configurations for the following elements of the actinide series of elements. Use noble gas and spdf notations. (a) Plutonium, Pu. The element is best known as a byproduct of nuclear power plant operations. (b) Curium, Cm. This actinide was named for Marie Curie (page 338 ).

What is the maximum number of electrons that can be identified with each of the following sets of quantum numbers? In some cases, the answer is "none." Explain why this is true. (a) \(n=4, \ell=3, m_{\ell}=1\) (b) \(n=6, \ell=1, m_{\ell}=-1, m_{\mathrm{s}}=-1 / 2\) (c) \(n=3, \ell=3, m_{\ell}=-3\)

What is the maximum number of electrons that can be identified with each of the following sets of quantum numbers? In some cases, the answer may be "none." In such cases, explain why "none" is the correct answer. (a) \(n=3\) (b) \(n=3\) and \(\ell=2\) (c) \(n=4, \ell=1, m_{\ell}=-1,\) and \(m_{s}=+1 / 2\) (d) \(n=5, \ell=0, m_{\ell}=-1, m_{\mathrm{s}}=+1 / 2\)

Depict the electron configuration for magnesium using an orbital box diagram and noble gas notation. Give a complete set of four quantum numbers for each of the electrons beyond those of the preceding noble gas.

Depict the electron configuration for phosphorus using an orbital box diagram and noble gas notation. Give one possible set of four quantum numbers for each of the electrons beyond those of the preceding noble gas.

Using an orbital box diagram and noble gas notation, show the electron configuration of gallium, Ga. Give a set of quantum numbers for the highest- energy electron.

Using an orbital box diagram and noble gas notation, show the electron configuration of titanium. Give one possible set of four quantum numbers for each of the electrons beyond those of the preceding noble gas.

Using orbital box diagrams, depict an electron configuration for each of the following ions: (a) \(\mathrm{Mg}^{2+}\) (b) \(\mathbf{K}^{+},\) (c) \(\mathbf{C l}^{-},\) and \((\mathbf{d}) \mathbf{O}^{2-}\).

Using orbital box diagrams, depict an electron configuration for each of the following ions: (a) \(\mathrm{Na}^{+}\) (b) \(\mathrm{Al}^{3+},\) (c) \(\mathrm{Ge}^{2+},\) and \((\mathrm{d}) \mathrm{F}^{-}\).

Using orbital box diagrams and noble gas notation, depict the electron configurations of (a) \(\mathrm{V},\) (b) \(\mathrm{V}^{2+},\) and (c) \(\mathrm{V}^{5+} .\) Are any of the ions paramagnetic?

Using orbital box diagrams and noble gas notation, depict the electron configurations of (a) Ti, (b) \(\mathrm{Ti}^{2+}\) and (c) Ti \(^{4+} .\) Are any of these paramagnetic?

Manganese is found as \(\mathrm{MnO}_{2}\) in deep ocean deposits. (a) Depict the electron configuration of this element using the noble gas notation and an orbital box diagram. (b) Using an orbital box diagram, show the electrons beyond those of the preceding noble gas for the \(4+\) ion. (c) Is the \(4+\) ion paramagnetic? (d) How many unpaired electrons does the Mn \(^{4+}\) ion have?

One compound found in alkaline batteries is \(\mathrm{NiOOH},\) a compound containing \(\mathrm{Ni}^{3+}\) ions. When the battery is discharged, the \(\mathrm{Ni}^{3+}\) is reduced to \(\mathrm{Ni}^{2+}\) ions las in \(\left.\mathrm{Ni}(\mathrm{OH})_{2}\right] .\) Using orbital box diagrams and the noble gas notation, show electron configurations of these ions. Ts either of these ions paramagnetic?

Arrange the following elements in order of increasing size: Al, B, C, K, and Na. (Try doing it without looking at Figure \(7.6,\) then check yourself by looking up the necessary atomic radii.)

Select the atom or ion in each pair that has the larger radius. (a) Cs or Rb (b) \(\mathrm{O}^{2-}\) or \(\mathrm{O}\) (c) Br or As

Which of the following groups of elements is arranged correctly in order of increasing ionization energy? (a) \(\mathrm{C}<\mathrm{Si}<\mathrm{Li}<\mathrm{Ne}\) (c) \(\mathrm{Li}<\mathrm{Si}<\mathrm{C}<\mathrm{Ne}\) (b) \(\mathrm{Ne}<\mathrm{Si}<\mathrm{C}<\mathrm{Li}\) (d) \(\mathrm{Ne}<\mathrm{C}<\mathrm{Si}<\mathrm{L}\) i

Arrange the following atoms in order of increasing ionization energy: \(\mathrm{Li}, \mathrm{K}, \mathrm{C},\) and \(\mathrm{N}\).

Compare the elements Na, Mg, O, and P. (a) Which has the largest atomic radius? (b) Which has the most negative electron attachment enthalpy? (c) Place the elements in order of increasing ionization energy.

Compare the elements \(\mathrm{B}, \mathrm{Al}, \mathrm{C},\) and \(\mathrm{Si}\) (a) Which has the most metallic character? (b) Which has the largest atomic radius? (c) Which has the most negative electron attachment enthalpy? (d) Place the three elements \(\mathrm{B}, \mathrm{Al}\), and \(\mathrm{C}\) in order of increasing first ionization energy.

Explain each answer briefly. (a) Place the following elements in order of increasing ionization energy: \(F, O,\) and \(S\) (b) Which has the largest ionization energy: O, S, or Se? (c) Which has the most negative electron attachment enthalpy: Se, Cl, or Br? (d) Which has the largest radius: \(\mathbf{O}^{2-}, \mathbf{F}^{-},\) or \(\mathrm{F} ?\)

Explain each answer briefly. (a) Rank the following in order of increasing atomic radius: \(\mathbf{O}, \mathbf{S},\) and \(\mathbf{F}\) (b) Which has the largest ionization energy: \(P\), Si, \(S\), or Se? (c) Place the following in order of increasing radius: \(\mathrm{O}^{2-}, \mathrm{N}^{3-},\) and \(\mathrm{F}^{-}\) (d) Place the following in order of increasing ionization energy: Cs, Sr, and Ba.

Using an orbital box diagram and noble gas notation, show the electron configurations of uranium and of the uranium(IV) ion. Is either of these paramagnetic?

The rare earth elements, or lanthanides, commonly exist as \(3+\) ions. Using an orbital box diagram and noble gas notation, show the electron configurations of the following elements and ions. (a) Ce and \(\mathrm{Ce}^{3+}\) (cerium) (b) Ho and \(\mathrm{Ho}^{3+}\) (holmium)

Element \(109,\) now named meitnerium (in honor of the Austrian-Swedish physicist, Lise Meitner \([1878-1968]\) ), was produced in August 1982 by a team at Germany's Institute for Heavy Ion Research. Depict its electron configuration using spdf and noble gas notations. Name another element found in the same group as meitnerium. (IMAGE CANNOT COPY) Lise Meitner \((1878-1968)\) and Otto Hahn \((1879-1968)\) Element 109 (Mt) was named after Meitner. She earned her Ph.D. in physics under Ludwig Boltzmann at the University of Vienna, and she was the first woman to earn a Ph.D. at that university.

A possible excited state for the H atom has an electron in a \(4 p\) orbital. List all possible sets of quantum numbers \(\left(n, \ell, m_{\ell}, m_{\mathrm{s}}\right)\) for this electron.

Name the element corresponding to each characteristic below. (a) the element with the electron configuration \(1 s^{2} 2 s^{2} 2 p^{6} 3 s^{2} 3 p^{3}\) (b) the alkaline earth element with the smallest atomic radius (c) the element with the largest ionization energy in Group \(5 \mathrm{A}\) (d) the element whose \(2+\) ion has the configuration \([\mathrm{Kr}] 4 d^{5}\) (e) the element with the most negative electron attachment enthalpy in Group \(7 \mathrm{A}\) (f) the element whose electron configuration is \([\mathrm{Ar}] 3 d^{10} 4 s^{2}\)

Arrange the following atoms in order of increasing ionization energy: Si, K, P, and Ca..

Rank the following in order of increasing ionization energy: Cl, \(\mathrm{Ca}^{2+}\), and \(\mathrm{Cl}^{-}\). Briefly explain your answer.

Answer the following questions about the elements with the electron configurations shown here: $$ A=[A r] 4 s^{2} \quad B=[A r] 3 d^{10} 4 s^{2} 4 p^{5} $$ (a) Is element A a metal, metalloid, or nonmetal? (b) Is element \(B\) a metal, metalloid, or nonmetal? (c) Which element is expected to have the larger ionization energy? (d) Which element has the smaller atomic radius?

Which of the following ions are unlikely to be found in a chemical compound: \(\mathrm{Cs}^{+}, \mathrm{In}^{4+}, \mathrm{Fe}^{6+}, \mathrm{Te}^{2-}, \mathrm{Sn}^{5+},\) and I'? Explain briefly.

Place the following ions in order of decreasing size: \(\mathbf{K}^{+}\) \(\mathrm{Cl}^{-}, \mathrm{S}^{2-},\) and \(\mathrm{Ca}^{2+}\).

Answer each of the following questions: (a) Of the elements \(\mathrm{S}\), Se, and Cl, which has the largest atomic radius? (b) Which has the larger radius, Br or Br'? (c) Which should have the largest difference between the first and second ionization energy: Si, Na, P, or Mg? (d) Which has the largest ionization energy: \(\mathrm{N}, \mathrm{P}\), or \(\mathrm{As}\) ? (e) Which of the following has the largest radius: \(\mathbf{O}^{2-}\) \(\mathrm{N}^{3-},\) or \(\mathrm{F}^{-} ?\)

A The following are isoelectronic species: \(\mathrm{Cl}^{-}, \mathrm{K}^{+},\) and \(\mathrm{Ca}^{2+} .\) Rank them in order of increasing (a) size, (b) ionization energy, and (c) electron attachment enthalpy.

Compare the elements \(\mathrm{Na}, \mathrm{B}, \mathrm{Al},\) and \(\mathrm{C}\) with regard to the following properties: (a) Which has the largest atomic radius? (b) Which has the most negative electron attachment enthalpy? (c) Place the elements in order of increasing ionization energy.

Two elements in the second transition series (Y through Cd) have four unpaired electrons in their 3+ ions. What elements fit this description?

Nickel(II) formate \(\left[\mathrm{Ni}\left(\mathrm{HCO}_{2}\right)_{2}\right]\) is widely used as a catalyst precursor and to make metallic nickel. It can be prepared in the general chemistry laboratory by treating nickel(II) acetate with formic acid (HCO,H). \(\mathrm{Ni}\left(\mathrm{CH}_{3} \mathrm{CO}_{2}\right)_{2}(\mathrm{aq})+2 \mathrm{HCO}_{2} \mathrm{H}(\mathrm{aq}) \rightarrow\) $$ \mathrm{Ni}\left(\mathrm{HCO}_{2}\right)_{2}(\mathrm{aq})+2 \mathrm{CH}_{3} \mathrm{CO}_{2} \mathrm{H}(\mathrm{aq}) $$ Green crystalline \(\mathrm{Ni}\left(\mathrm{HCO}_{2}\right)_{2}\) is precipitated after adding ethanol to the solution. (a) What is the theoretical yield of nickel(II) formate from 0.500 g of nickel(II) acetate and excess formic acid? (b) Is nickel(II) formate paramagnetic or diamagnetic? If it is paramagnetic, how many unpaired electrons would you expect? (c) If nickel(II) formate is heated to \(300^{\circ} \mathrm{C}\) in the absence of air for 30 minutes, the salt decomposes to form pure nickel powder. What mass of nickel powder should be produced by heating 253 mg of nickel(II) formate? Are nickel atoms paramagnetic?

Why is the radius of \(\mathrm{Li}^{+}\) so much smaller than the radius of Li? Why is the radius of \(\mathrm{F}^{-}\) so much larger than the radius of F?

Which ions in the following list are not likely to be found in chemical compounds: \(\mathrm{K}^{2+}, \mathrm{Cs}^{+}, \mathrm{Al}^{4+}, \mathrm{F}^{2-},\) and \(\mathrm{Se}^{2-} ?\) Explain briefly.

The ionization of the hydrogen atom can be calculated from Bohr's equation for the electron energy. $$ E=-(N R h c)\left(Z^{2} / n^{2}\right) $$ where \(N R h c=1312 \mathrm{kJ} / \mathrm{mol}\) and \(Z\) is the atomic number. Let us use this approach to calculate a possible ionization energy for helium. First, assume the electrons of the He experience the full \(2+\) nuclear charge. This gives us the upper limit for the ionization energy. Next, assume one electron of He completely screens the nuclear charge from the other electrons, so \(Z=1 .\) This gives us a lower limit to the ionization energy. Compare these calculated values for the upper and lower limits to the experimental value of \(2372.3 \mathrm{kJ} / \mathrm{mol} .\) What does this tell us about the ability of one electron to screen the nuclear charge?

Write electron configurations to show the first two ionization processes for potassium. Explain why the second ionization energy is much greater than the first.

What is the trend in ionization energy when proceeding down a group in the periodic table. Rationalize this trend.

(a) Explain why the sizes of atoms change when proceeding across a period of the periodic table. (b) Explain why the sizes of transition metal atoms change very little across a period.