Chemistry and Chemical Reactivity

John C. Kotz, Paul M. Treichel, John R. Townsend, David A. Treichel

Chapter 7

The Structure of Atoms and Periodic Trends - all with Video Answers

Educators

Chapter Questions

Problem 1

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.

Sam Limsuwannarot

Sam Limsuwannarot

Numerade Educator

Problem 2

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

Elaine Velicaria

Elaine Velicaria

Numerade Educator

Problem 3

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

Sam Limsuwannarot

Sam Limsuwannarot

Numerade Educator

Problem 4

Using spdf notation, give the electron configuration of vanadium, $\mathrm{V},$ an element found in some brown and red algae and some toadstools.

Sam Limsuwannarot

Sam Limsuwannarot

Numerade Educator

Problem 5

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, and larger amounts are poisonous.
(b) Krypton, Kr. It ranks seventh in abundance of the gases in Earth's atmosphere.

Elaine Velicaria

Elaine Velicaria

Numerade Educator

Problem 6

Using spdf and noble gas notations, write electron configurations for atoms of the following elements. (Try to do this by looking at the periodic table but not at Table $7.3 .$ )
(a) Strontium, Sr. This element is named for a town in Scotland.
(b) Zirconium, Zr. The metal is exceptionally resistant to corrosion and so has important industrial applications. Moon rocks show a surprisingly high zirconium content compared with rocks on Earth.
(c) Rhodium, Rh. This metal is used in jewelry and in catalysts in industry.
(d) Tin, Sn. The metal was used in the ancient world. Alloys of tin (solder, bronze, and pewter) are important.

Elaine Velicaria

Elaine Velicaria

Numerade Educator

Problem 7

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 preColumbian 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).

Elaine Velicaria

Elaine Velicaria

Numerade Educator

Problem 8

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.

Sam Limsuwannarot

Sam Limsuwannarot

Numerade Educator

Problem 9

Americium, Am, is a radioactive element isolated from spent fuel in nuclear reactors and used in home smoke detectors. Depict its electron configuration using noble gas and spdf notations.

Elaine Velicaria

Elaine Velicaria

Numerade Educator

Problem 10

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 by-product of nuclear power plant operations.
(b) Curium, Cm. This actinide was named for Marie Curie (page 72 ).

Elaine Velicaria

Elaine Velicaria

Numerade Educator

Problem 11

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) $n=4, \ell=3, m_{\ell}=1$
(b) $n=6, \ell=1, m_{\ell}=-1, m_{\mathrm{s}}=-1 / 2$
(c) $n=3, \ell=3, m_{c}=-3$

Lottie Adams

Numerade Educator

Problem 12

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 $m_{\mathrm{s}}=+1 / 2$
(d) $n=5, \ell=0, m_{\ell}=-1, m_{\mathrm{s}}=+1 / 2$

Lottie Adams

Numerade Educator

Problem 13

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.

Sam Limsuwannarot

Sam Limsuwannarot

Numerade Educator

Problem 14

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.

Sam Limsuwannarot

Sam Limsuwannarot

Numerade Educator

Problem 15

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

Lottie Adams

Numerade Educator

Problem 16

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.

Sam Limsuwannarot

Sam Limsuwannarot

Numerade Educator

Problem 17

The effective nuclear charge, $Z^{*},$ is the net force of attraction experienced by the outermost electron in an atom. Which of the following statements best describes how $Z^{*}$ varies among the elements of the second period (Li to $\mathrm{F}$ )?
(a) regular increase from Li to $\mathrm{F}$
(b) regular decrease from Li to $\mathrm{F}$
(c) general increase from Li to F, but with exceptions

Lottie Adams

Numerade Educator

Problem 18

Which of the following statements correctly describes the value of the effective nuclear charge, $Z^{*},$ felt by
(a) the $2 s$ electron at a large distance from a Li atom?
(i) $\quad Z^{*}$ equals 1
(ii) $Z^{*}$ is between 1 and 3
(iii) $Z^{*}$ equals 3
(b) the $2 s$ electron at its most probable distance from the nucleus of a Li atom?
(i) $\quad Z^{*}$ equals 1
(ii) $Z^{*}$ is between 1 and 3
(iii) $Z^{*}$ equals 3

Lottie Adams

Numerade Educator

Problem 19

List the first five orbitals (the five orbitals in an atom at lowest energy) in order of filling, according to the Aufbau principle.

Elaine Velicaria

Elaine Velicaria

Numerade Educator

Problem 20

The values of $n$ and $\ell$ are useful to determine the order of filling (Aufbau principle). Use $n$ and $\ell$ to determine which orbital, $4 f, 5 d,$ or $6 s,$ will fill first.

Elaine Velicaria

Elaine Velicaria

Numerade Educator

Problem 21

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

Sam Limsuwannarot

Sam Limsuwannarot

Numerade Educator

Problem 22

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

Sam Limsuwannarot

Sam Limsuwannarot

Numerade Educator

Problem 23

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

Lottie Adams

Numerade Educator

Problem 23

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

Lottie Adams

Numerade Educator

Problem 24

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

Lottie Adams

Numerade Educator

Problem 25

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 $\mathrm{Mn}^{4+}$
(c) Is $\mathrm{Mn}^{4+}$ paramagnetic?
(d) How many unpaired electrons does the $\mathrm{Mn}^{4+}$ ion have?

Lottie Adams

Numerade Educator

Problem 26

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

Lottie Adams

Numerade Educator

Problem 27

Arrange the following elements in order of increasing size: $\mathrm{Al}, \mathrm{B}, \mathrm{C}, \mathrm{K},$ and $\mathrm{Na}$. (Try doing it without looking at Figure $7.5 ;$ then check yourself by looking up the necessary atomic radii.)

Elaine Velicaria

Elaine Velicaria

Numerade Educator

Problem 28

Arrange the following elements in order of increasing size: Ca, Rb, P, Ge, and Sr. (Try doing it without looking at Figure $7.5 ;$ then check yourself by looking up the necessary atomic radii.

Arun Bana

Numerade Educator

Problem 29

Select the atom or ion in each pair that has the larger radius.
(a) $\mathrm{Cl}$ or $\mathrm{Cl}^{-}$ (b) Al or $\mathrm{O}$
(c) In or I

Sam Limsuwannarot

Sam Limsuwannarot

Numerade Educator

Problem 30

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

Sam Limsuwannarot

Sam Limsuwannarot

Numerade Educator

Problem 31

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) $\mathrm{Ne} < \mathrm{C} < \mathrm{Si} < \mathrm{Li}$

Sam Limsuwannarot

Sam Limsuwannarot

Numerade Educator

Problem 32

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

Elaine Velicaria

Elaine Velicaria

Numerade Educator

Problem 33

Compare the elements $\mathrm{Na}, \mathrm{Mg}, \mathrm{O},$ and $\mathrm{P}$
(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.

Elaine Velicaria

Elaine Velicaria

Numerade Educator

Problem 34

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.

Elaine Velicaria

Elaine Velicaria

Numerade Educator

Problem 35

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

Elaine Velicaria

Elaine Velicaria

Numerade Educator

Problem 36

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

Sam Limsuwannarot

Sam Limsuwannarot

Numerade Educator

Problem 37

Identify the element that corresponds to each of the simplified photoelectron spectral data given below. (Energy data taken from D. A. Shirley, R. L. Martin, S. P. Kowalczyk, F. R. McFeely, and L. Ley:
"Core-electron binding energies of the first thirty elements," Physical Review B, Vol. 15, pp. 544-552, $1977 .)$
(a) There are peaks at energies of 64.8 and $5.4 \mathrm{eV}$ corresponding to 2 and 1 electrons, respectively.
(b) There are peaks at energies of 3614,384,301 $40.9,24.7,$ and $4.34 \mathrm{eV},$ corresponding to 2,2
$6,2,6,$ and 1 electrons, respectively.
(c) There are peaks at energies of 4494,503,404 $56.4,33.6,8.01,$ and $6.65 \mathrm{eV},$ corresponding to
$2,2,6,2,6,1,$ and 2 electrons, respectively.

Lottie Adams

Numerade Educator

Problem 38

Identify the element that corresponds to each of the simplified photoelectron spectral data given below. (Energy data taken from D. A. Shirley, R. L. Martin, S. P. Kowalczyk, F. R. McFeely, and L. Ley:
"Core-electron binding energies of the first thirty elements," Physical Review B, Vol. 15, pp. 544-552, $1977 .)$
(a) There are peaks at energies corresponding to $1079,70.8,38.0,5.14 \mathrm{eV},$ corresponding to 2 $2,6,$ and 1 electrons, respectively.
(b) There are peaks at energies corresponding to $4043,443,351,48.4,30.1,$ and $6.11 \mathrm{eV},$ corre-
sponding to $2,2,6,2,6,$ and 2 electrons, respectively.
(c) There are peaks at energies corresponding to $5475,638,524,77,47,12,$ and $7.3 \mathrm{eV},$ corre-
sponding to $2,2,6,2,6,3,$ and 2 electrons, respectively.

Lottie Adams

Numerade Educator

Problem 39

Explain why the photoelectron spectra of hydrogen and helium each has one peak whereas that for lithium has two peaks. What would be the relative intensity of each of the peaks in these spectra?

Lottie Adams

Numerade Educator

Problem 41

The red color of rubies is the result of the substitution of some $\mathrm{Cr}^{3+}$ ions for $\mathrm{Al}^{3+}$ ions in solid $\mathrm{Al}_{2} \mathrm{O}_{3}$.
(a) Using spáf notation with the noble gas notation, write the electron configuration for the Cr atom and for the $\mathrm{Cr}^{3+}$ ion?
(b) Is $\mathrm{Cr}^{2+}$ paramagnetic? Is $\mathrm{Cr}^{3+} ?$
(c) The radius of the $\mathrm{Cr}^{3+}$ ion is $64 \mathrm{pm}$. How does this compare with the radius of the $\mathrm{Al}^{3+}$ ion?

Rajesh Singh

Numerade Educator

Problem 42

The deep blue color of sapphires comes from the presence of $\mathrm{Fe}^{2+}$ and $\mathrm{Ti}^{4+}$ in solid $\mathrm{Al}_{2} \mathrm{O}_{3}$. Using $s p d$ notation with the noble gas notation, write the electron configuration for each of these ions.

Lottie Adams

Numerade Educator

Problem 43

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?

Sam Limsuwannarot

Sam Limsuwannarot

Numerade Educator

Problem 44

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)

Sam Limsuwannarot

Sam Limsuwannarot

Numerade Educator

Problem 45

A neutral atom has two electrons with $n=1,$ eight electrons with $n=2$, eight electrons with $n=3$ and two electrons with $n=4 .$ Assuming this element is in its ground state, supply the following information:
(a) atomic number
(b) total number of $s$ electrons
(c) total number of $p$ electrons
(d) total number of $d$ electrons
(e) Is the element a metal, metalloid, or nonmetal?

Vishal Sharma

Numerade Educator

Problem 46

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 lon Research. Depict its electron configuration using spdf and noble gas notations. Name another element found in the same group as meitnerium.

Lottie Adams

Numerade Educator

Problem 47

Which of the following is not an allowable set of quantum numbers? Explain your answer briefly. For those sets that are valid, identify an element in which an outermost valence electron could have that set of quantum numbers.

Lottie Adams

Numerade Educator

Problem 48

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

Lottie Adams

Numerade Educator

Problem 49

The magnet in the following photo is made from neodymium, iron, and boron.
(a) Write the electron configuration of each of these elements using an orbital box diagram and noble gas notation.
(b) Are these elements paramagnetic or diamagnetic?
(c) Write the electron configurations of $\mathrm{Nd}^{3+}$ and $\mathrm{Fe}^{3+}$ using orbital box diagrams and noble gas notation. Are these ions paramagnetic or diamagnetic?

Lottie Adams

Numerade Educator

Problem 50

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 7A
(f) the element whose electron configuration is $[\mathrm{Ar}] 3 d^{10} 4 s^{2}$

Lottie Adams

Numerade Educator

Problem 51

Arrange the following atoms in order of increasing ionization energy: $\mathrm{Si}, \mathrm{K}, \mathrm{P},$ and $\mathrm{Ca}$

Sam Limsuwannarot

Sam Limsuwannarot

Numerade Educator

Problem 52

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

Sam Limsuwannarot

Sam Limsuwannarot

Numerade Educator

Problem 53

Answer the questions below about the elements A and $\mathrm{B},$ which have the electron configurations shown.
$$
\mathrm{A}=[\mathrm{Kr}] 5 s^{1} \quad \mathrm{B}=\left[\mathrm{Ar} | 3 d^{10} 4 \mathrm{s}^{2} 4 p^{4}\right.
$$
(a) Is element $A$ a metal, nonmetal, or metalloid?
(b) Which element has the greater ionization energy?
(c) Which element has the less negative electron attachment enthalpy?
(d) Which element has the larger atomic radius?
(e) What is the formula for a compound formed between A and B?

Lottie Adams

Numerade Educator

Problem 54

Answer the following questions about the elements with the electron configurations shown here:
$$
A=\left[\begin{array}{ll}
A r & 4 s^{2} & B=|A r| 3 d^{10} 4 s^{2} 4 p^{5}
\end{array}\right.
$$
(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?

Sam Limsuwannarot

Sam Limsuwannarot

Numerade Educator

Problem 55

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 $\mathrm{I}^{-} ?$ Explain briefly.

Sam Limsuwannarot

Sam Limsuwannarot

Numerade Educator

Problem 56

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

Lottie Adams

Numerade Educator

Problem 57

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

Lottie Adams

Numerade Educator

Problem 58

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.

Lottie Adams

Numerade Educator

Problem 59

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.

Elaine Velicaria

Elaine Velicaria

Numerade Educator

Problem 60

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

Sam Limsuwannarot

Sam Limsuwannarot

Numerade Educator

Problem 61

The configuration for an element is given here.
(a) What is the identity of the element with this configuration?
(b) Is a sample of the element paramagnetic or diamagnetic?
(c) How many unpaired electrons does a $3+$ ion of this element have?

Lottie Adams

Numerade Educator

Problem 62

The configuration of an element is given here.
(a) What is the identity of the element?
(b) In what group and period is the element found?
(c) Is the element a nonmetal, a main group element, a transition metal, a lanthanide, or an actinide?
(d) Is the element diamagnetic or paramagnetic? If paramagnetic, how many unpaired electrons are there?
(e) Write a complete set of quantum numbers
$\left(n, \ell, m_{c}, m_{s}\right)$ for each of the valence electrons.
(f) What is the configuration of the $2+$ ion formed from this element? Is the ion diamagnetic or paramagnetic?

Lottie Adams

Numerade Educator

Problem 63

Answer the questions below about the elements $A$ and $\mathrm{B},$ which have the ground state electron configurations shown.
$$
\mathrm{A}=[\mathrm{Kr}] 5 s^{2} \quad \mathrm{B}=|\mathrm{Kr}| 4 d^{10} 5 s^{2} 5 p^{5}
$$
(a) Is element $A$ a metal, nonmetal, or metalloid?
(b) Which element has the greater ionization energy?
(c) Which element has a larger atomic radius?
(d) Which element has the more negative electron attachment enthalpy?
(e) Which is more likely to form a cation?
(f) What is a likely formula for a compound formed between A and B?

Lottie Adams

Numerade Educator

Problem 64

Answer the questions below concerning ground state electron configurations.
(a) What element has the electron configuration $[\mathrm{Ar}] 3 d^{6} 4 s^{2} ?$
(b) What element has a $2+$ ion with the configuration $[\mathrm{Ar}] 3 d^{3} ?$ Is the ion paramagnetic or diamagnetic?
(c) How many unpaired electrons are in a $\mathrm{Ni}^{2+}$ ion?
(d) The configuration for an element is given here.
What is the identity of the element? Is a sample of the element paramagnetic or diamagnetic? How many unpaired electrons does a $3-$ ion of this element have?
(e) What element has the following electron configuration? Write a complete set of quantum numbers for electrons $1-3$

Rajesh Singh

Numerade Educator

Problem 65

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 $\left(\mathrm{HCO}_{2} \mathrm{H}\right)$
$$
\mathrm{Ni}\left(\mathrm{CH}_{3} \mathrm{CO}_{2}\right)_{2}(\mathrm{aq})+2 \mathrm{HCO}_{2} \mathrm{H}(\mathrm{aq}) \rightarrow
$$
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( $(\mathrm{II})$ 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 $253 \mathrm{mg}$ of nickel( II) formate? Are nickel atoms paramagnetic?

Lottie Adams

Numerade Educator

Problem 66

A Spinels are solids with the general formula $\mathrm{M}^{2+}\left(\mathrm{M}^{\prime 3+}\right)_{2} \mathrm{O}_{4}$ (where $\mathrm{M}^{2+}$ and $\mathrm{M}^{\prime 3+}$ are metal
cations of the same or different metals). The bestknown example is common magnetite, $\mathrm{Fe}_{3} \mathrm{O}_{4}$ Iwhich you can formulate as $\left.\left(\mathrm{Fe}^{2+}\right)\left(\mathrm{Fe}^{3+}\right)_{2} \mathrm{O}_{4}\right]$
(a) Given its name, it is evident that magnetite is ferromagnetic. How many unpaired electrons are in iron(II) and in iron(III) ions?
(b) Two other spinels are $\operatorname{CoAl}_{2} \mathrm{O}_{4}$ and $\mathrm{Sn} \mathrm{Co}_{2} \mathrm{O}_{4}$
What metal ions are involved in each? What are their electron configurations? Are the metal ions paramagnetic, and if so, how many unpaired electrons are involved?

Lottie Adams

Numerade Educator

Problem 67

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

Sam Limsuwannarot

Sam Limsuwannarot

Numerade Educator

Problem 68

Which ions in the following list are not likely to be found in chemical compounds: $\mathbf{K}^{2+}, \mathbf{C s}^{+}, \mathbf{A} \mathbf{l}^{4+}, \mathbf{F}^{2-}$
and $\mathrm{Se}^{2-}$ ? Explain briefly.

Lottie Adams

Numerade Educator

Problem 69

Answer the following questions about first ionization energies.
(a) Generally ionization energies increase on proceeding across a period, but this is not true for magnesium $(738 \mathrm{kJ} / \mathrm{mol})$ and aluminum $(578 \mathrm{kJ} / \mathrm{mol}) .$ Explain this observation.
(b) Explain why the ionization energy of phosphorus $(1012 \mathrm{kJ} / \mathrm{mol})$ is greater than that of sulfur $(1000 \mathrm{kJ} / \mathrm{mol})$ when the general trend in ionization energies in a period would predict the opposite.

Elaine Velicaria

Elaine Velicaria

Numerade Educator

Problem 70

A The ionization of the hydrogen atom can be calculated from Bohr's equation for the electron energy.
$$
E=-\left(N_{A} R h c\right)\left(Z^{2} / n^{2}\right)
$$
where $N_{A} R h c=1312 \mathrm{kJ} / \mathrm{mol}$ 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?

Rajesh Singh

Numerade Educator

Problem 71

Compare the configurations below with two electrons located in $p$ orbitals. Which would be the most stable (have the lowest energy)? Which would be the least stable? Explain your answers.

Lottie Adams

Numerade Educator

Problem 72

The bond lengths in $\mathrm{Cl}_{2}, \mathrm{Br}_{2},$ and $\mathrm{I}_{2}$ are 200,228 and $266 \mathrm{pm},$ respectively. Knowing that the tin radius is $141 \mathrm{pm},$ estimate the bond distances in $\mathrm{Sn}-\mathrm{Cl}, \mathrm{Sn}-\mathrm{Br},$ and $\mathrm{Sn}-\mathrm{I} .$ Compare the estimated
values with the experimental values of 233,250 and $270 \mathrm{pm},$ respectively.

Lottie Adams

Numerade Educator

Problem 73

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

Sam Limsuwannarot

Sam Limsuwannarot

Numerade Educator

Problem 74

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

Elaine Velicaria

Elaine Velicaria

Numerade Educator

Problem 75

(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.

Sam Limsuwannarot

Sam Limsuwannarot

Numerade Educator

Problem 76

Which of the following elements has the greatest difference between its first and second ionization energies: $\mathrm{C}, \mathrm{Li}, \mathrm{N},$ Be? Explain your answer.

Sam Limsuwannarot

Sam Limsuwannarot

Numerade Educator

Problem 77

A What arguments would you use to convince another student in general chemistry that $\mathrm{MgO}$ consists of the ions $\mathrm{Mg}^{2+}$ and $\mathrm{O}^{2-}$ and not the ions $\mathrm{Mg}^{+}$ and $\mathrm{O}^{-2}$. What experiments could be done to provide some evidence that the correct formulation of magnesium oxide is $\mathrm{Mg}^{2+} \mathrm{O}^{2-} ?$

Lottie Adams

Numerade Educator

Problem 78

Explain why the first ionization energy of Ca is greater than that of $K$, whereas the second ionization energy of Ca is lower than the second ionization energy of K.

Sam Limsuwannarot

Sam Limsuwannarot

Numerade Educator

Problem 79

The energies of the orbitals in many elements have been determined. For the first two periods they have the following values:
(a) $\Delta$ Why do the orbital energies generally become more negative on proceeding across the second period?
(b) How are these values related to the ionization energy and electron attachment enthalpy of the elements?
(c) Use these energy values to explain the observation that the ionization energies of the first four second-period elements are in the order $\mathrm{Li}<\mathrm{Be}>\mathrm{B}<\mathrm{C}$
(Data from J. B. Mann, T. L. Meek, and L. C. Allen:
Journal of the American Chemical Society, Vol. 122
p. $2780,2000 .$ )

Lottie Adams

Numerade Educator

Problem 80

A The ionization energies for the removal of the first electron in $\mathrm{Si}, \mathrm{P}, \mathrm{S},$ and $\mathrm{Cl}$ are as listed in the table below. Briefly rationalize this trend.

Elaine Velicaria

Elaine Velicaria

Numerade Educator

Problem 81

Using your knowledge of the trends in element sizes on going across the periodic table, explain briefly why the density of the elements increases from K through V.

Lottie Adams

Numerade Educator

Problem 82

The densities (in $\mathrm{g} / \mathrm{cm}^{3}$ ) of elements in Groups $6 \mathrm{B}$, $8 \mathrm{B},$ and $1 \mathrm{B}$ are given in the table below.
Period $4 \quad$ Cr, 7.19 Co, 8.90 $\mathrm{Cu}, 8.96$
Period $5 \quad$ Mo, $10.22 \quad$ Rh, $12.41 \quad$ Ag, 10.50
Period $6 \quad \mathrm{W}, 19.30 \quad$ Ir, $22.56 \quad$ Au, 19.32
Transition metals in the sixth period all have much greater densities than the elements in the same groups in the fourth and fifth periods. Refer to Figure $7.8,$ and explain this observation.

Lottie Adams

Numerade Educator

Problem 83

The discovery of two new elements (atomic numbers 113 and 115 ) was announced in February
2004.
(a) Use spáf and noble gas notations to give the electron configurations of these two elements.
(b) For each of these elements, name another element in the same periodic group.
(c) Element 113 was made by firing the nucleus of a light atom at a heavy americium atom. The two nuclei combine to give a nucleus with
113 protons. What light atom was used as a projectile?

Lottie Adams

Numerade Educator

Problem 84

Explain why the reaction of calcium and fluorine does not form $\mathrm{CaF}_{3}$

Sam Limsuwannarot

Sam Limsuwannarot

Numerade Educator

Problem 85

A Thionyl chloride, $\operatorname{SOCl}_{2}$, is an important chlorinating and oxidizing agent in organic chemistry. It is prepared industrially by oxygen atom transfer from $\mathrm{SO}_{3}$ to $\mathrm{SCl}_{2}$
$$
\mathrm{SO}_{3}(\mathrm{g})+\mathrm{SCl}_{2}(\mathrm{g}) \rightarrow \mathrm{SO}_{2}(\mathrm{g})+\mathrm{SOCl}_{2}(\mathrm{g})
$$
(a) Give the electron configuration for an atom of sulfur using an orbital box diagram. Do not use the noble gas notation.
(b) Using the configuration given in part (a), write a set of quantum numbers for the highestenergy electron in a sulfur atom.
(c) What element involved in this reaction (O, $S$, Cl) should have the smallest ionization energy? The smallest radius?
(d) Which should be smaller: the sulfide ion, $S^{2-}$ or a sulfur atom, $\mathbf{S} ?$
(e) If you want to make 675 g of $\operatorname{SOCl}_{2}$, what mass of $\mathrm{SCl}_{2}$ is required?
(f) If you use $10.0 \mathrm{g}$ of $\mathrm{SO}_{3}$ and $10.0 \mathrm{g}$ of $\mathrm{SCl}_{2}$ what is the theoretical yield of $\mathrm{SOCl}_{2} ?$
(g) $\Delta_{i} H^{\circ}$ for the reaction of $\mathrm{SO}_{3}$ and $\mathrm{SCl}_{2}$ is $-96.0 \mathrm{kJ} / \mathrm{mol} \mathrm{SOCl}_{2}$ produced. Using data in
Appendix I, calculate the standard molar enthalpy of formation of $\mathrm{SCl}_{2}$

Lottie Adams

Numerade Educator

Problem 86

Sodium metal reacts readily with chlorine gas to give sodium chloride.
$$
\mathrm{Na}(\mathrm{s})+1 / 2 \mathrm{C}_{2}(\mathrm{g}) \rightarrow \mathrm{NaCl}(\mathrm{s})
$$
(a) What is the reducing agent in this reaction? What property of the element contributes to its ability to act as a reducing agent?
(b) What is the oxidizing agent in this reaction? What property of the element contributes to its ability to act as an oxidizing agent?
(c) Why does the reaction produce NaCl and not a compound such as $\mathrm{Na}_{2} \mathrm{Cl}$ or $\mathrm{NaCl}_{2} ?$

Lottie Adams

Numerade Educator

Problem 87

A Slater's rules are a way to estimate the effective nuclear charge experienced by an electron. In this approach, the "shielding constant, " $S$, is calculated. The effective nuclear charge is then the difference between $S$ and the atomic number, $Z$. (Note that the results in Table 7.2 and Figure 7.2 were calculated in a slightly different way.)
$$
Z^{*}=Z-S
$$

Lottie Adams

Numerade Educator