Chemistry

Raymond Chang, Jason Overby

Chapter 8

Periodic Relationships Among the Elements - all with Video Answers

Educators

+ 5 more educators

Chapter Questions

Problem 1

Briefly describe the significance of Mendeleev's periodic table.

Simon Kangoun

Simon Kangoun

Numerade Educator

Problem 2

What is Moseley's contribution to the modern periodic table?

Brooke Troxell

Numerade Educator

Problem 3

Describe the general layout of a modern periodic table.

RC

Ryan Carlson

Numerade Educator

Problem 4

What is the most important relationship among elements in the same group in the periodic table?

Brooke Troxell

Numerade Educator

Problem 5

Which of the following elements are metals, nonmetals, or metalloids? As, Xe, Fe, Li, B, Cl, Ba, $\mathrm{P}, \mathrm{I}, \mathrm{Si}$

Crystal Wang

Numerade Educator

Problem 6

Compare the physical and chemical properties of metals and nonmetals.

Brooke Troxell

Numerade Educator

Problem 7

Draw a rough sketch of a periodic table (no details are required). Indicate regions where metals, nonmetals, and metalloids are located.

RC

Ryan Carlson

Numerade Educator

Problem 8

What is a representative element? Give names and symbols of four representative elements.

Brooke Troxell

Numerade Educator

Problem 9

Without referring to a periodic table, write the name and give the symbol for an element in each of the following groups: $1 \mathrm{~A}, 2 \mathrm{~A}, 3 \mathrm{~A}, 4 \mathrm{~A}, 5 \mathrm{~A}, 6 \mathrm{~A}, 7 \mathrm{~A}, 8 \mathrm{~A},$ transition metals.

RC

Ryan Carlson

Numerade Educator

Problem 10

Indicate whether the following elements exist as atomic species, molecular species, or extensive threedimensional structures in their most stable states at $25^{\circ} \mathrm{C}$ and 1 atm and write the molecular or empirical formula for each one: phosphorus, iodine, magnesium, neon, carbon, sulfur, cesium, and oxygen.

Lottie Adams

Numerade Educator

Problem 11

You are given a dark shiny solid and asked to determine whether it is iodine or a metallic element. Suggest a nondestructive test that would enable you to arrive at the correct answer.

RC

Ryan Carlson

Numerade Educator

Problem 12

What are valence electrons? For representative elements, the number of valence electrons of an element is equal to its group number. Show that this is true for the following elements: $\mathrm{Al}, \mathrm{Sr}, \mathrm{K}, \mathrm{Br}, \mathrm{P}, \mathrm{S}, \mathrm{C}$

Brooke Troxell

Numerade Educator

Problem 13

Write the outer electron configurations for the
(a) alkali metals, (b) alkaline earth metals, (c) halogens,
(d) noble gases.

RC

Ryan Carlson

Numerade Educator

Problem 14

Use the first-row transition metals (Sc to Cu) as an example to illustrate the characteristics of the electron configurations of transition metals.

Lottie Adams

Numerade Educator

Problem 15

The electron configurations of ions derived from representative elements follow a common pattern. What is the pattern, and how does it relate to the stability of these ions?

RC

Ryan Carlson

Numerade Educator

Problem 16

What do we mean when we say that two ions or an atom and an ion are isoelectronic?

Brooke Troxell

Numerade Educator

Problem 17

What is wrong with the statement "The atoms of element $\mathrm{X}$ are isoelectronic with the atoms of element $\mathrm{Y}^{\prime \prime} ?$

RC

Ryan Carlson

Numerade Educator

Problem 18

Give three examples of first-row transition metal (Sc to Cu) ions whose electron configurations are represented by the argon core.

Brooke Troxell

Numerade Educator

Problem 19

In the periodic table, the element hydrogen is sometimes grouped with the alkali metals (as in this book) and sometimes with the halogens. Explain why hydrogen can resemble the Group 1 A and the Group 7A elements.

RC

Ryan Carlson

Numerade Educator

Problem 20

A neutral atom of a certain element has 17 electrons. Without consulting a periodic table, (a) write the ground-state electron configuration of the element,
(b) classify the element, (c) determine whether this element is diamagnetic or paramagnetic.

Brooke Troxell

Numerade Educator

Problem 21

Group the following electron configurations in pairs that would represent similar chemical properties of their atoms:
(a) $1 s^{2} 2 s^{2} 2 p^{6} 3 s^{2}$
(b) $1 s^{2} 2 s^{2} 2 p^{3}$
(c) $1 s^{2} 2 s^{2} 2 p^{6} 3 s^{2} 3 p^{6} 4 s^{2} 3 d^{10} 4 p^{6}$
(d) $1 s^{2} 2 s^{2}$
(e) $1 s^{2} 2 s^{2} 2 p^{6}$
(f) $1 s^{2} 2 s^{2} 2 p^{6} 3 s^{2} 3 p^{3}$

Lottie Adams

Numerade Educator

Problem 22

Group the following electron configurations in pairs that would represent similar chemical properties of their atoms:
(a) $1 s^{2} 2 s^{2} 2 p^{5}$
(b) $1 s^{2} 2 s^{1}$
(c) $1 s^{2} 2 s^{2} 2 p^{6}$
(d) $1 s^{2} 2 s^{2} 2 p^{6} 3 s^{2} 3 p^{5}$
(e) $1 s^{2} 2 s^{2} 2 p^{6} 3 s^{2} 3 p^{6} 4 s^{1}$
(f) $1 s^{2} 2 s^{2} 2 p^{6} 3 s^{2} 3 p^{6} 4 s^{2} 3 d^{10} 4 p^{6}$

Brooke Troxell

Numerade Educator

Problem 23

Without referring to a periodic table, write the electron configuration of elements with the following atomic numbers: (a) 9 ,
(b) 20 ,
(c) 26
(d) 33 . Classify the elements.

RC

Ryan Carlson

Numerade Educator

Problem 24

Specify the group of the periodic table in which each of the following elements is found: (a) $[\mathrm{Ne}] 3 s^{1}$,
(b) $[\mathrm{Ne}] 3 s^{2} 3 p^{3}$,
(c) $[\mathrm{Ne}] 3 s^{2} 3 p^{6}$,
(d) $[\mathrm{Ar}] 4 s^{2} 3 d^{8}$.

Simon Kangoun

Numerade Educator

Problem 25

A $\mathrm{M}^{2+}$ ion derived from a metal in the first transition metal series has four electrons in the $3 d$ subshell. What element might $\mathrm{M}$ be?

Lottie Adams

Numerade Educator

Problem 26

A metal ion with a net +3 charge has five electrons in the $3 d$ subshell. Identify the metal.

Brooke Troxell

Numerade Educator

Problem 27

Write the ground-state electron configurations of the following ions:
(a) $\mathrm{Li}^{+},(\mathrm{b}) \mathrm{H}^{-},(\mathrm{c}) \mathrm{N}^{3-},(\mathrm{d}) \mathrm{F}^{-}$ (e) $\mathrm{S}^{2-}$, (f) $\mathrm{Al}^{3+},(\mathrm{g}) \mathrm{Se}^{2-},(\mathrm{h}) \mathrm{Br}^{-},(\mathrm{i}) \mathrm{Rb}^{+},(\mathrm{j}) \mathrm{Sr}^{2+}$
(k) $\mathrm{Sn}^{2+},$ (1) $\mathrm{Te}^{2-},(\mathrm{m}) \mathrm{Ba}^{2+},(\mathrm{n}) \mathrm{Pb}^{2+},(\mathrm{o}) \mathrm{In}^{3+}$
(p) $\mathrm{Tl}^{+},(\mathrm{q}) \mathrm{Tl}^{3+}$

Vishal Sharma

Numerade Educator

Problem 28

Write the ground-state electron configurations of the following ions, which play important roles in biochemical processes in our bodies:
(a) $\mathrm{Na}^{+}$,
(b) $\mathrm{Mg}^{2+},(\mathrm{c}) \mathrm{Cl}^{-},(\mathrm{d}) \mathrm{K}^{+},(\mathrm{e}) \mathrm{Ca}^{2+},(\mathrm{f}) \mathrm{Fe}^{2+},(\mathrm{g}) \mathrm{Cu}^{2+}$
(h) $\mathrm{Zn}^{2+}$.

Brooke Troxell

Numerade Educator

Problem 29

Write the ground-state electron configurations of the following transition metal ions: (a) $\mathrm{Sc}^{3+}$,
(b) $\mathrm{Ti}^{4+},(\mathrm{c}) \mathrm{V}^{5+},(\mathrm{d}) \mathrm{Cr}^{3+},(\mathrm{e}) \mathrm{Mn}^{2+},(\mathrm{f}) \mathrm{Fe}^{2+},(\mathrm{g}) \mathrm{Fe}^{3+}$
(h) $\mathrm{Co}^{2+}$
(i) $\mathrm{Ni}^{2+},$ (j) $\mathrm{Cu}^{+},(\mathrm{k}) \mathrm{Cu}^{2+}$
(l) $\mathrm{Ag}^{+}$
$(\mathrm{m}) \mathrm{Au}^{+},(\mathrm{n}) \mathrm{Au}^{3+},(\mathrm{o}) \mathrm{Pt}^{2+}$

Lottie Adams

Numerade Educator

Problem 30

Name the ions with +3 charges that have the following electron configurations:
(a) $[\mathrm{Ar}] 3 d^{3}$,
(b) [Ar],
(c) $[\mathrm{Kr}] 4 d^{6}$,
(d) $[\mathrm{Xe}] 4 f^{14} 5 d^{6}$.

Brooke Troxell

Numerade Educator

Problem 31

Which of the following species are isoelectronic with each other? $\mathrm{C}, \mathrm{Cl}^{-}, \mathrm{Mn}^{2+}, \mathrm{B}^{-}, \mathrm{Ar}, \mathrm{Zn}, \mathrm{Fe}^{3+}, \mathrm{Ge}^{2+}$

RC

Ryan Carlson

Numerade Educator

Problem 32

Group the species that are isoelectronic: $\mathrm{Be}^{2+}, \mathrm{F}^{-}$ $\mathrm{Fe}^{2+}, \mathrm{N}^{3-}, \mathrm{He}, \mathrm{S}^{2-}, \mathrm{Co}^{3+}, \mathrm{Ar}$

Brooke Troxell

Numerade Educator

Problem 33

Define atomic radius. Does the size of an atom have a precise meaning?

RC

Ryan Carlson

Numerade Educator

Problem 34

How does atomic radius change (a) from left to right across a period and (b) from top to bottom in a group?

Simon Kangoun

Numerade Educator

Problem 35

Define ionic radius. How does the size of an atom change when it is converted to (a) an anion and
(b) a cation?

RC

Ryan Carlson

Numerade Educator

Problem 36

Explain why, for isoelectronic ions, the anions are larger than the cations.

Matthew Glaub

Numerade Educator

Problem 37

On the basis of their positions in the periodic table, select the atom with the larger atomic radius in each of the following pairs:
(a) $\mathrm{Na}, \mathrm{Cs} ;$ (b) $\mathrm{Be}, \mathrm{Ba} ;$ (c) $\mathrm{N}$,
$\mathrm{Sb} ;(\mathrm{d}) \mathrm{F}, \mathrm{Br} ;(\mathrm{e}) \mathrm{Ne}, \mathrm{Xe}$

RC

Ryan Carlson

Numerade Educator

Problem 38

Arrange the following atoms in order of decreasing atomic radius: $\mathrm{Na}, \mathrm{Al}, \mathrm{P}, \mathrm{Cl}, \mathrm{Mg} .$

Matthew Glaub

Numerade Educator

Problem 39

Which is the largest atom in Group $4 \mathrm{~A} ?$

RC

Ryan Carlson

Numerade Educator

Problem 40

Which is the smallest atom in Group 7A?

Anand Jangid

Numerade Educator

Problem 41

Why is the radius of the lithium atom considerably larger than the radius of the hydrogen atom?

Simon Kangoun

Numerade Educator

Problem 42

Use the second period of the periodic table as an example to show that the size of atoms decreases as we move from left to right. Explain the trend.

Simon Kangoun

Numerade Educator

Problem 43

Indicate which one of the two species in each of the following pairs is smaller: (a) $\mathrm{Cl}$ or $\mathrm{Cl}^{-} ;$ (b) Na or $\mathrm{Na}^{+}$;
(c) $\mathrm{O}^{2-}$ or $\mathrm{S}^{2-}$
(d) $\mathrm{Mg}^{2+}$ or $\mathrm{Al}^{3+}$
(e) $\mathrm{Au}^{+}$ or $\mathrm{Au}^{3+}$

RC

Ryan Carlson

Numerade Educator

Problem 44

List the following ions in order of increasing ionic radius: $\mathrm{N}^{3-}, \mathrm{Na}^{+}, \mathrm{F}^{-}, \mathrm{Mg}^{2+}, \mathrm{O}^{2-}$

Lottie Adams

Numerade Educator

Problem 45

Explain which of the following cations is larger, and why: $\mathrm{Cu}^{+}$ or $\mathrm{Cu}^{2+}$

RC

Ryan Carlson

Numerade Educator

Problem 46

Explain which of the following anions is larger, and why: $\mathrm{Se}^{2-}$ or $\mathrm{Te}^{2-}$

Matthew Glaub

Numerade Educator

Problem 47

Give the physical states (gas, liquid, or solid) of the representative elements in the fourth period $(\mathrm{K}, \mathrm{Ca},$ $\mathrm{Ga}, \mathrm{Ge}, \mathrm{As}, \mathrm{Se}, \mathrm{Br})$ at $1 \mathrm{~atm}$ and $25^{\circ} \mathrm{C}$

Crystal Wang

Numerade Educator

Problem 48

Both $\mathrm{H}^{-}$ and He contain two $1 s$ electrons. Which species is larger? Explain your choice.

Lottie Adams

Numerade Educator

Problem 49

Define ionization energy. Ionization energy measurements are usually made when atoms are in the gaseous state. Why? Why is the second ionization energy always greater than the first ionization energy for any element?

RC

Ryan Carlson

Numerade Educator

Problem 50

Sketch the outline of the periodic table and show group and period trends in the first ionization energy of the elements. What types of elements have the highest ionization energies and what types the lowest ionization energies?

Matthew Glaub

Numerade Educator

Problem 51

Arrange the following in order of increasing first ionization energy: $\mathrm{Na}, \mathrm{Cl}, \mathrm{Al}, \mathrm{S},$ and $\mathrm{Cs}$

Simon Kangoun

Numerade Educator

Problem 52

Arrange the following in order of increasing first ionization energy: $\mathrm{F}, \mathrm{K}, \mathrm{P}, \mathrm{Ca},$ and $\mathrm{Ne} .$

Simon Kangoun

Numerade Educator

Problem 53

Use the third period of the periodic table as an example to illustrate the change in first ionization energies of the elements as we move from left to right. Explain the trend.

RC

Ryan Carlson

Numerade Educator

Problem 54

In general, ionization energy increases from left to right across a given period. Aluminum, however, has a lower ionization energy than magnesium. Explain.

Matthew Glaub

Numerade Educator

Problem 55

The first and second ionization energies of $\mathrm{K}$ are 419 kJ/mol and $3052 \mathrm{~kJ} / \mathrm{mol}$, and those of Ca are $590 \mathrm{~kJ} / \mathrm{mol}$ and $1145 \mathrm{~kJ} / \mathrm{mol},$ respectively. Compare their values and comment on the differences.

RC

Ryan Carlson

Numerade Educator

Problem 56

Two atoms have the electron configurations $1 s^{2} 2 s^{2} 2 p^{6}$ and $1 s^{2} 2 s^{2} 2 p^{6} 3 s^{1} .$ The first ionization energy of one is $2080 \mathrm{~kJ} / \mathrm{mol}$, and that of the other is $496 \mathrm{~kJ} / \mathrm{mol} .$ Match each ionization energy with one of the given electron configurations. Justify your choice.

Simon Kangoun

Numerade Educator

Problem 57

A hydrogenlike ion contains only one electron. The energies of the electron in a hydrogenlike ion are given by
$$
E_{n}=-\left(2.18 \times 10^{-18} \mathrm{~J}\right) Z^{2}\left(\frac{1}{n^{2}}\right)
$$
where $n$ is the principal quantum number and $Z$ is the atomic number of the element. Calculate the ionization energy (in $\mathrm{kJ} / \mathrm{mol}$ ) of the $\mathrm{He}^{+}$ ion.

Anand Jangid

Numerade Educator

Problem 58

Plasma is a state of matter consisting of positive gaseous ions and electrons. In the plasma state, a mercury atom could be stripped of its 80 electrons and therefore would exist as $\mathrm{Hg}^{80+}$. Use the equation in Problem 8.57 to calculate the energy required for the last ionization step, that is,
$$
\mathrm{Hg}^{79+}(g) \longrightarrow \mathrm{Hg}^{80+}(g)+e^{-}
$$

Lottie Adams

Numerade Educator

Problem 59

(a) Define electron affinity. (b) Electron affinity measurements are made with gaseous atoms. Why?
(c) Ionization energy is always a positive quantity, whereas electron affinity may be either positive or negative. Explain.

Lottie Adams

Numerade Educator

Problem 60

Explain the trends in electron affinity from aluminum to chlorine (see Table 8.3 ).

Matthew Glaub

Numerade Educator

Problem 61

Arrange the elements in each of the following groups in increasing order of the most positive electron affinity: (a) $\mathrm{Li}, \mathrm{Na}, \mathrm{K} ;(\mathrm{b}) \mathrm{F}, \mathrm{Cl}, \mathrm{Br}, \mathrm{I} ;(\mathrm{c}) \mathrm{O}, \mathrm{Si},$
$\mathrm{P}, \mathrm{Ca}, \mathrm{Ba}$

Lottie Adams

Numerade Educator

Problem 62

Specify which of the following elements you would expect to have the greatest electron affinity and which would have the least: $\mathrm{He}, \mathrm{K}, \mathrm{Co}, \mathrm{S}, \mathrm{Cl}$

Matthew Glaub

Numerade Educator

Problem 63

Considering their electron affinities, do you think it is possible for the alkali metals to form an anion like $\mathrm{M}^{-},$ where $\mathrm{M}$ represents an alkali metal?

RC

Ryan Carlson

Numerade Educator

Problem 64

Explain why alkali metals have a greater affinity for electrons than alkaline earth metals.

Matthew Glaub

Numerade Educator

Problem 65

What is meant by the diagonal relationship? Name two pairs of elements that show this relationship.

RC

Ryan Carlson

Numerade Educator

Problem 66

Which elements are more likely to form acidic oxides? Basic oxides? Amphoteric oxides?

Lottie Adams

Numerade Educator

Problem 67

Use the alkali metals and alkaline earth metals as examples to show how we can predict the chemical properties of elements simply from their electron configurations.

RC

Ryan Carlson

Numerade Educator

Problem 68

Based on your knowledge of the chemistry of the alkali metals, predict some of the chemical properties of francium, the last member of the group.

Matthew Glaub

Numerade Educator

Problem 69

As a group, the noble gases are very stable chemically (only $\mathrm{Kr}$ and Xe are known to form compounds). Use the concepts of shielding and the effective nuclear charge to explain why the noble gases tend to neither give up electrons nor accept additional electrons.

RC

Ryan Carlson

Numerade Educator

Problem 70

Why are Group $1 \mathrm{~B}$ elements more stable than Group 1A elements even though they seem to have the same outer electron configuration, $n s^{1},$ where $n$ is the principal quantum number of the outermost shell?

Lottie Adams

Numerade Educator

Problem 71

How do the chemical properties of oxides change from left to right across a period? From top to bottom within a particular group?

Lottie Adams

Numerade Educator

Problem 72

Write balanced equations for the reactions between each of the following oxides and water:
(a) $\mathrm{Li}_{2} \mathrm{O}$
(b) $\mathrm{CaO},$ (c) $\mathrm{SO}_{3}$.

Matthew Glaub

Numerade Educator

Problem 73

Write formulas for and name the binary hydrogen compounds of the second-period elements (Li to F). Describe how the physical and chemical properties of these compounds change from left to right across the period.

RC

Ryan Carlson

Numerade Educator

Problem 74

Which oxide is more basic, $\mathrm{MgO}$ or $\mathrm{BaO}$ ? Why?

Lottie Adams

Numerade Educator

Problem 75

State whether each of the following properties of the representative elements generally increases or decreases (a) from left to right across a period and
(b) from top to bottom within a group: metallic character, atomic size, ionization energy, acidity of oxides.

RC

Ryan Carlson

Numerade Educator

Problem 76

With reference to the periodic table, name (a) a halogen element in the fourth period, (b) an element similar to phosphorus in chemical properties, (c) the most reactive metal in the fifth period, (d) an element that has an atomic number smaller than 20 and is similar to strontium.

Matthew Glaub

Numerade Educator

Problem 77

Write equations representing the following processes:
(a) The electron affinity of $\mathrm{S}^{-}$
(b) The third ionization energy of titanium
(c) The electron affinity of $\mathrm{Mg}^{2+}$
(d) The ionization energy of $\mathrm{O}^{2-}$

RC

Ryan Carlson

Numerade Educator

Problem 78

List all the common ions of representative elements and transition metals that are isoelectronic with Ar.

Matthew Glaub

Numerade Educator

Problem 79

Write the empirical (or molecular) formulas of compounds that the elements in the third period (sodium to chlorine) should form with (a) molecular oxygen and (b) molecular chlorine. In each case indicate whether you would expect the compound to be ionic or molecular in character.

RC

Ryan Carlson

Numerade Educator

Problem 80

Element $\mathrm{M}$ is a shiny and highly reactive metal (melting point $\left.63^{\circ} \mathrm{C}\right)$, and element $\mathrm{X}$ is a highly reactive nonmetal (melting point $-7.2^{\circ} \mathrm{C}$ ). They react to form a compound with the empirical formula MX, a colorless, brittle white solid that melts at $734^{\circ} \mathrm{C} .$ When dissolved in water or when in the molten state, the substance conducts electricity. When chlorine gas is bubbled through an aqueous solution containing MX, a reddish-brown liquid appears and $\mathrm{Cl}^{-}$ ions are formed. From these observations, identify $\mathrm{M}$ and $\mathrm{X}$. (You may need to consult a handbook of chemistry for the melting-point values.)

Lottie Adams

Numerade Educator

Problem 81

Match each of the elements on the right with its description on the left:
(a) A dark-red liquid
(b) A colorless gas that burns in oxygen gas
(c) A reactive metal that attacks water
(d) A shiny metal that is used in jewelry
(e) An inert gas
Calcium (Ca) Gold (Au) Hydrogen $\left(\mathrm{H}_{2}\right)$ Argon (Ar) Bromine $\left(\mathrm{Br}_{2}\right)$

RC

Ryan Carlson

Numerade Educator

Problem 82

Arrange the following species in isoelectronic pairs:
$\mathrm{O}^{+}, \mathrm{Ar}, \mathrm{S}^{2-}, \mathrm{Ne}, \mathrm{Zn}, \mathrm{Cs}^{+}, \mathrm{N}^{3-}, \mathrm{As}^{3+}, \mathrm{N}, \mathrm{Xe}$

Matthew Glaub

Numerade Educator

Problem 83

In which of the following are the species written in decreasing order by size of radius?
(a) Be, Mg, Ba;
(b) $\mathrm{N}^{3-}, \mathrm{O}^{2-}, \mathrm{F}^{-} ;(\mathrm{c}) \mathrm{Tl}^{3+}, \mathrm{Tl}^{2+}, \mathrm{Tl}^{+}$

Crystal Wang

Numerade Educator

Problem 84

Which of the following properties show a clear periodic variation: (a) first ionization energy, (b) molar mass of the elements, (c) number of isotopes of an element, (d) atomic radius?

Matthew Glaub

Numerade Educator

Problem 85

When carbon dioxide is bubbled through a clear calcium hydroxide solution, the solution appears milky. Write an equation for the reaction and explain how this reaction illustrates that $\mathrm{CO}_{2}$ is an acidic oxide.

RC

Ryan Carlson

Numerade Educator

Problem 86

You are given four substances: a fuming red liquid, a dark metallic-looking solid, a pale-yellow gas, and a yellow-green gas that attacks glass. You are told that these substances are the first four members of Group 7A, the halogens. Name each one.

Matthew Glaub

Numerade Educator

Problem 87

Calculate the change in energy for the following
processes:
(a) $\mathrm{Na}(g)+\mathrm{Cl}(g) \longrightarrow \mathrm{Na}^{+}(g)+\mathrm{Cl}^{-}(g)$
(b) $\mathrm{Ca}(g)+2 \mathrm{Br}(g) \longrightarrow \mathrm{Ca}^{2+}(g)+2 \mathrm{Br}^{-}(g)$

RC

Ryan Carlson

Numerade Educator

Problem 88

Calculate the change in energy for the following processes:
(a) $\mathrm{Mg}(g)+2 \mathrm{~F}(g) \longrightarrow \mathrm{Mg}^{2+}(g)+2 \mathrm{~F}^{-}(g)$
(b) $2 \mathrm{Al}(g)+3 \mathrm{O}(g) \longrightarrow 2 \mathrm{Al}^{3+}(g)+3 \mathrm{O}^{2-}(g)$
The electron affinity of $\mathrm{O}^{-}$ is $-844 \mathrm{~kJ} / \mathrm{mol} .$

Lottie Adams

Numerade Educator

Problem 89

For each pair of elements listed, give three properties that show their chemical similarity: (a) sodium and potassium,
(b) chlorine and bromine.

Lottie Adams

Numerade Educator

Problem 90

Name the element that forms compounds, under appropriate conditions, with every other element in the periodic table except He, Ne, and Ar.

Lottie Adams

Numerade Educator

Problem 91

Explain why the first electron affinity of sulfur is $200 \mathrm{~kJ} / \mathrm{mol}$ but the second electron affinity is $-649 \mathrm{~kJ} / \mathrm{mol} .$

Lottie Adams

Numerade Educator

Problem 92

The $\mathrm{H}^{-}$ ion and the $\mathrm{He}$ atom have two $1 s$ electrons each. Which of the two species is larger? Explain.

Lottie Adams

Numerade Educator

Problem 93

Predict the products of the following oxides with water: $\mathrm{Na}_{2} \mathrm{O}, \mathrm{BaO}, \mathrm{CO}_{2}, \mathrm{~N}_{2} \mathrm{O}_{5}, \mathrm{P}_{4} \mathrm{O}_{10}, \mathrm{SO}_{3} .$ Write an
equation for each of the reactions. Specify whether the oxides are acidic, basic, or amphoteric.

Lottie Adams

Numerade Educator

Problem 94

Write the formulas and names of the oxides of the second-period elements (Li to $\mathrm{N}$ ). Identify the oxides as acidic, basic, or amphoteric.

Lottie Adams

Numerade Educator

Problem 95

State whether each of the following elements is a gas, a liquid, or a solid under atmospheric conditions. Also state whether it exists in the elemental form as atoms, as molecules, or as a three-dimensional network: $\mathrm{Mg}, \mathrm{Cl}, \mathrm{Si}, \mathrm{Kr}, \mathrm{O}, \mathrm{I}, \mathrm{Hg}, \mathrm{Br}$

Lottie Adams

Numerade Educator

Problem 96

What factors account for the unique nature of hydrogen?

Lottie Adams

Numerade Educator

Problem 97

The air in a manned spacecraft or submarine needs to be purified of exhaled carbon dioxide. Write equations for the reactions between carbon dioxide and (a) lithium oxide $\left(\mathrm{Li}_{2} \mathrm{O}\right),$ (b) sodium peroxide $\left(\mathrm{Na}_{2} \mathrm{O}_{2}\right),$ and $(\mathrm{c})$ potassium superoxide $\left(\mathrm{KO}_{2}\right)$

Lottie Adams

Numerade Educator

Problem 98

The formula for calculating the energies of an electron in a hydrogenlike ion is given in Problem 8.57 . This equation cannot be applied to many-electron atoms. One way to modify it for the more complex atoms is to replace $Z$ with $(Z-\sigma),$ where $Z$ is the atomic number and $\sigma$ is a positive dimensionless quantity called the shielding constant. Consider the helium atom as an example. The physical significance of $\sigma$ is that it represents the extent of shielding that the two $1 s$ electrons exert on each other. Thus, the quantity $(Z-\sigma)$ is appropriately called the "effective nuclear charge." Calculate the value of $\sigma$ if the first ionization energy of helium is $3.94 \times$ $10^{-18} \mathrm{~J}$ per atom. (Ignore the minus sign in the given equation in your calculation.)

Lottie Adams

Numerade Educator

Problem 99

Why do noble gases have negative electron affinity values?

RC

Ryan Carlson

Numerade Educator

Problem 100

The atomic radius of $\mathrm{K}$ is $227 \mathrm{pm}$ and that of $\mathrm{K}^{+}$ is $133 \mathrm{pm} .$ Calculate the percent decrease in volume that occurs when $\mathrm{K}(g)$ is converted to $\mathrm{K}^{+}(g) .$ [The volume of a sphere is $\left(\frac{4}{3}\right) \pi r^{3},$ where $r$ is the radius of the sphere.]

Lottie Adams

Numerade Educator

Problem 101

The atomic radius of $\mathrm{F}$ is $72 \mathrm{pm}$ and that of $\mathrm{F}^{-}$ is $133 \mathrm{pm} .$ Calculate the percent increase in volume that occurs when $\mathrm{F}(g)$ is converted to $\mathrm{F}^{-}(g) .$ (See Problem 8.100 for the volume of a sphere.)

Lottie Adams

Numerade Educator

Problem 102

A technique called photoelectron spectroscopy is used to measure the ionization energy of atoms. A sample is irradiated with UV light, and electrons are ejected from the valence shell. The kinetic energies of the ejected electrons are measured. Because the energy of the UV photon and the kinetic energy of the ejected electron are known, we can write
$$
h \nu=I E+\frac{1}{2} m u^{2}
$$
where $\nu$ is the frequency of the UV light, and $m$ and $u$ are the mass and velocity of the electron, respectively. In one experiment the kinetic energy of the ejected electron from potassium is found to be $5.34 \times 10^{-19} \mathrm{~J}$ using a UV source of wavelength $162 \mathrm{nm} .$ Calculate the ionization energy of potassium. How can you be sure that this ionization energy corresponds to the electron in the valence shell (that is, the most loosely held electron)?

Jean Gephart

Numerade Educator

Problem 103

Referring to the Chemistry in Action essay "Discovery of the Noble Gases" in Section 8.6 , answer the following questions: (a) Why did it take so long to discover the first noble gas (argon) on Earth? (b) Once argon had been discovered, why did it take relatively little time to discover the rest of the noble gases? (c) Why was helium not isolated by the fractional distillation of liquid air?

Anand Jangid

Numerade Educator

Problem 104

The energy needed for the following process is 1.96 $\times 10^{4} \mathrm{~kJ} / \mathrm{mol}$
$$
\mathrm{Li}(g) \longrightarrow \mathrm{Li}^{3+}(g)+3 e^{-}
$$
If the first ionization energy of lithium is $520 \mathrm{~kJ} /$ mol, calculate the second ionization energy of lithium, that is, the energy required for the process
$$
\mathrm{Li}(g) \longrightarrow \mathrm{Li}^{3+}(g)+3 e^{-}
$$
(Hint: You need the equation in Problem $8.57 .)$

David Collins

Numerade Educator

Problem 105

An element X reacts with hydrogen gas at $200^{\circ} \mathrm{C}$ to form compound Y. When $Y$ is heated to a higher temperature, it decomposes to the element $X$ and hydrogen gas in the ratio of $559 \mathrm{~mL}$ of $\mathrm{H}_{2}$ (measured at STP) for $1.00 \mathrm{~g}$ of $\mathrm{X}$ reacted. $\mathrm{X}$ also combines with chlorine to form a compound $Z,$ which contains 63.89 percent by mass of chlorine. Deduce the identity of $X$.

Crystal Wang

Numerade Educator

Problem 106

A student is given samples of three elements, $\mathrm{X}, \mathrm{Y}$, and $\mathrm{Z}$, which could be an alkali metal, a member of Group $4 \mathrm{~A},$ and a member of Group $5 \mathrm{~A} .$ She makes the following observations: Element X has a metallic luster and conducts electricity. It reacts slowly with hydrochloric acid to produce hydrogen gas. Element $Y$ is a light-yellow solid that does not conduct electricity. Element $Z$ has a metallic luster and conducts electricity. When exposed to air, it slowly forms a white powder. A solution of the white powder in water is basic. What can you conclude about the elements from these observations?

Lottie Adams

Numerade Educator

Problem 107

Identify the ions whose orbital diagrams for the valence electrons are shown. The charges of the ions
are:
(a) $1+,(b) 3+,(c) 4+,(d) 2+$

Lottie Adams

Numerade Educator

Problem 108

What is the electron affinity of the $\mathrm{Na}^{+}$ ion?

Lottie Adams

Numerade Educator

Problem 109

The ionization energies of sodium (in $\mathrm{kJ} / \mathrm{mol}$ ), starting with the first and ending with the eleventh, are 495.9,4560,6900,9540,13,400,16,600,20,120
$25,490,28,930,141,360,170,000 .$ Plot the $\log$ of ionization energy ( $y$ axis) versus the number of ionization $(x$ axis $) ;$ for example, log 495.9 is plotted versus 1 (labeled $I E_{1}$, the first ionization energy), $\log 4560$ is plotted versus 2 (labeled $I E_{2}$, the second ionization energy), and so on. (a) Label $I E_{1}$ through $I E_{11}$ with the electrons in orbitals such as $1 s, 2 s, 2 p$ and $3 s .$ (b) What can you deduce about electron shells from the breaks in the curve?

Lottie Adams

Numerade Educator

Problem 110

Experimentally, the electron affinity of an element can be determined by using a laser light to ionize the anion of the element in the gas phase:
$$
\mathrm{X}^{-}(g)+h \nu \longrightarrow \mathrm{X}(g)+e^{-}
$$
Referring to Table $8.3,$ calculate the photon wavelength (in nanometers) corresponding to the electron affinity for chlorine. In what region of the electromagnetic spectrum does this wavelength fall?

David Collins

Numerade Educator

Problem 111

Explain, in terms of their electron configurations, why $\mathrm{Fe}^{2+}$ is more easily oxidized to $\mathrm{Fe}^{3+}$ than $\mathrm{Mn}^{2+}$ is to $\mathrm{Mn}^{3+}$

Lottie Adams

Numerade Educator

Problem 112

The standard enthalpy of atomization of an element is the energy required to convert one mole of an element in its most stable form at $25^{\circ} \mathrm{C}$ to one mole of monatomic gas. Given that the standard enthalpy of atomization for sodium is $108.4 \mathrm{~kJ} / \mathrm{mol}$, calculate the energy in kilojoules required to convert one mole of sodium metal at $25^{\circ} \mathrm{C}$ to one mole of gaseous $\mathrm{Na}^{+}$ ions.

Lottie Adams

Numerade Educator

Problem 113

Write the formulas and names of the hydrides of the following second-period elements: $\mathrm{Li}, \mathrm{C}, \mathrm{N}, \mathrm{O}, \mathrm{F}$ Predict their reactions with water.

Lottie Adams

Numerade Educator

Problem 114

Based on knowledge of the electronic configuration of titanium, state which of the following compounds of titanium is unlikely to exist: $\mathrm{K}_{3} \mathrm{TiF}_{6}, \mathrm{~K}_{2} \mathrm{Ti}_{2} \mathrm{O}_{5}$
$\mathrm{TiCl}_{3}, \mathrm{~K}_{2} \mathrm{TiO}_{4}, \mathrm{~K}_{2} \mathrm{TiF}_{6}$

Lottie Adams

Numerade Educator

Problem 115

Name an element in Group $1 \mathrm{~A}$ or Group $2 \mathrm{~A}$ that is an important constituent of each of the following substances: (a) remedy for acid indigestion,
(b) coolant in nuclear reactors, (c) Epsom salt, (d) baking powder, (e) gunpowder, (f) a light alloy, (g) fertilizer that also neutralizes acid rain, (h) cement, and
(i) grit for icy roads. You may need to ask your instructor about some of the items.

Lottie Adams

Numerade Educator

Problem 116

In halogen displacement reactions a halogen element can be generated by oxidizing its anions with a halogen element that lies above it in the periodic table. This means that there is no way to prepare elemental fluorine, because it is the first member of Group 7A. Indeed, for years the only way to prepare elemental fluorine was to oxidize $\mathrm{F}$ ions by electrolytic means. Then, in $1986,$ a chemist reported that by reacting potassium hexafluoromanganate(IV) $\left(\mathrm{K}_{2} \mathrm{MnF}_{6}\right)$ with antimony pentafluoride $\left(\mathrm{SbF}_{5}\right)$ at $150^{\circ} \mathrm{C},$ he had generated elemental fluorine. Balance the following equation representing the reaction:
$$
\mathrm{K}_{2} \mathrm{MnF}_{6}+\mathrm{SbF}_{5} \longrightarrow \mathrm{KSbF}_{6}+\mathrm{MnF}_{3}+\mathrm{F}_{2}
$$

Susan Hallstrom

Susan Hallstrom

Numerade Educator

Problem 117

Write a balanced equation for the preparation of
(a) molecular oxygen, (b) ammonia, (c) carbon dioxide,
(d) molecular hydrogen, (e) calcium oxide. Indicate the physical state of the reactants and products in each equation.

Lottie Adams

Numerade Educator

Problem 118

Write chemical formulas for oxides of nitrogen with the following oxidation numbers: $+1,+2,+3,+4,$ +5. (Hint: There are two oxides of nitrogen with +4 oxidation number.)

Lottie Adams

Numerade Educator

Problem 119

Most transition metal ions are colored. For example, a solution of $\mathrm{CuSO}_{4}$ is blue. How would you show that the blue color is due to the hydrated $\mathrm{Cu}^{2+}$ ions and not the $\mathrm{SO}_{4}^{2-}$ ions?

Lottie Adams

Numerade Educator

Problem 120

In general, atomic radius and ionization energy have opposite periodic trends. Why?

Matthew Glaub

Numerade Educator

Problem 121

Explain why the electron affinity of nitrogen is approximately zero, while the elements on either side, carbon and oxygen, have substantial positive electron affinities.

Lottie Adams

Numerade Educator

Problem 122

Consider the halogens chlorine, bromine, and iodine. The melting point and boiling point of chlorine are $-101.0^{\circ} \mathrm{C}$ and $-34.6^{\circ} \mathrm{C}$ while those of iodine are $113.5^{\circ} \mathrm{C}$ and $184.4^{\circ} \mathrm{C},$ respectively. Thus, chlorine is a gas and iodine is a solid under room conditions. Estimate the melting point and boiling point of bromine. Compare your values with those from a handbook of chemistry.

Lottie Adams

Numerade Educator

Problem 123

Write a balanced equation that predicts the reaction of rubidium (Rb) with
(a) $\mathrm{H}_{2} \mathrm{O}(l)$
(b) $\mathrm{Cl}_{2}(g)$
(c) $\mathrm{H}_{2}(g)$

Lottie Adams

Numerade Educator

Problem 124

The successive $I E$ of the first four electrons of a representative element are $738.1 \mathrm{~kJ} / \mathrm{mol}, 1450 \mathrm{~kJ} / \mathrm{mol},$
$7730 \mathrm{~kJ} / \mathrm{mol},$ and $10,500 \mathrm{~kJ} / \mathrm{mol} .$ Characterize the
element according to the periodic group.

Ronald Prasad

Numerade Educator

Problem 125

Little is known of the chemistry of astatine, the last member of Group 7A. Describe the physical characteristics that you would expect this halogen to have. Predict the products of the reaction between sodium astatide (NaAt) and sulfuric acid. (Hint: Sulfuric acid is an oxidizing agent.)

Lottie Adams

Numerade Educator

Problem 126

As discussed in the chapter, the atomic mass of argon is greater than that of potassium. This observation created a problem in the early development of the periodic table because it meant that argon should be placed after potassium. (a) How was this difficulty resolved?
(b) From the following data, calculate the average atomic masses of argon and potassium: Ar-36 (35.9675 amu; 0.337 percent), $\begin{array}{lll}\text { Ar- } 38 & (37.9627 & \text { amu } ; & 0.063 \text { percent), } & \text { Ar-40 }\end{array}$ $(39.9624 \mathrm{amu} ; 99.60$ percent $) ; \mathrm{K}-39(38.9637 \mathrm{amu} ;$
93.258 percent $,$ K- 40 ( 39.9640 amu; 0.0117 percent), K-41 $(40.9618$ amu; 6.730 percent).

Crystal Wang

Numerade Educator

Problem 127

Calculate the maximum wavelength of light (in nanometers) required to ionize a single sodium atom.

Jean Gephart

Numerade Educator

Problem 128

Predict the atomic number and ground-state electron configuration of the next member of the alkali metals after francium.

Lottie Adams

Numerade Educator

Problem 129

Why do elements that have high ionization energies also have more positive electron affinities? Which group of elements would be an exception to this generalization?

Lottie Adams

Numerade Educator

Problem 130

The first four ionization energies of an element are approximately $579 \mathrm{~kJ} / \mathrm{mol}, 1980 \mathrm{~kJ} / \mathrm{mol}, 2963 \mathrm{~kJ} /$
mol, and $6180 \mathrm{~kJ} / \mathrm{mol}$. To which periodic group does this element belong?

Cheryl Glor

Numerade Educator

Problem 131

Some chemists think that helium should properly be called "helon." Why? What does the ending in helium (-ium) suggest?

Lottie Adams

Numerade Educator

Problem 132

(a) The formula of the simplest hydrocarbon is $\mathrm{CH}_{4}$ (methane). Predict the formulas of the simplest compounds formed between hydrogen and the following elements: silicon, germanium, tin, and lead.
(b) Sodium hydride (NaH) is an ionic compound. Would you expect rubidium hydride (RbH) to be more or less ionic than NaH? (c) Predict the reaction between radium (Ra) and water. (d) When exposed to air, aluminum forms a tenacious oxide $\left(\mathrm{Al}_{2} \mathrm{O}_{3}\right)$ coating that protects the metal from corrosion. Which metal in Group 2 A would you expect to exhibit similar properties? Why?

Lottie Adams

Numerade Educator

Problem 133

Give equations to show that molecular hydrogen can act both as a reducing agent and an oxidizing agent.

Lottie Adams

Numerade Educator

Problem 134

Both $\mathrm{Mg}^{2+}$ and $\mathrm{Ca}^{2+}$ are important biological ions. One of their functions is to bind to the phosphate groups of ATP molecules or amino acids of proteins. For Group 2 A metals in general, the tendency for binding to the anions increases in the order $\mathrm{Ba}^{2+}$ $<\mathrm{Sr}^{2+}<\mathrm{Ca}^{2+}<\mathrm{Mg}^{2+} .$ Explain the trend.

Anand Jangid

Numerade Educator

Problem 135

Match each of the elements on the right with its description on the left:
(a) A pale yellow gas that reacts with water.
(b) A soft metal that reacts with water to produce hydrogen.
(c) A metalloid that is hard and has a high melting point.
(d) A colorless, odorless gas.
(e) A metal that is more reactive than iron, but does not corrode in air.
Nitrogen $\left(\mathrm{N}_{2}\right)$
Boron (B)
Aluminum (Al)
Fluorine $\left(\mathrm{F}_{2}\right)$
Sodium (Na)

Lottie Adams

Numerade Educator

Problem 136

Write an account on the importance of the periodic table. Pay particular attention to the significance of the position of an element in the table and how the position relates to the chemical and physical properties of the element.

Crystal Wang

Numerade Educator

Problem 137

On the same graph, plot the effective nuclear charge (see Section 8.3 ) and atomic radius (see Figure 8.5 ) versus atomic number for the second-period elements Li to Ne. Comment on the trends.

Susan Hallstrom

Susan Hallstrom

Numerade Educator

Problem 138

One allotropic form of an element $X$ is a colorless crystalline solid. The reaction of $\mathrm{X}$ with an excess amount of oxygen produces a colorless gas. This gas dissolves in water to yield an acidic solution. Choose one of the following elements that matches $\mathrm{X}:$ (a) sulfur, (b) phosphorus, (c) carbon, (d) boron, and (e) silicon.

Lottie Adams

Numerade Educator

Problem 139

When magnesium metal is burned in air, it forms two products $A$ and $B$. A reacts with water to form a basic solution. B reacts with water to form a similar
solution as that of A plus a gas with a pungent odor. Identify A and $\mathrm{B}$ and write equations for the reactions. (Hint: See Chemistry in Action essay "Discovery of the Noble Gases" in Section $8.6 .$ )

Anand Jangid

Numerade Educator

Problem 140

The ionization energy of a certain element is $412 \mathrm{~kJ} /$ mol. When the atoms of this element are in the first excited state, however, the ionization energy is only $126 \mathrm{~kJ} / \mathrm{mol} .$ Based on this information, calculate the wavelength of light emitted in a transition from the first excited state to the ground state.

Lottie Adams

Numerade Educator

Problem 141

Use your knowledge of thermochemistry to calculate the $\Delta H$ for the following processes:
(a) $\mathrm{Cl}^{-}(g) \longrightarrow$
$\mathrm{Cl}^{+}(g)+2 e^{-} ;(\mathrm{b}) \mathrm{K}^{+}(g)+2 e^{-} \longrightarrow \mathrm{K}^{-}(g)$

Lottie Adams

Numerade Educator

Problem 142

Referring to Table $8.2,$ explain why the first ionization energy of helium is less than twice the ionization energy of hydrogen, but the second ionization energy of helium is greater than twice the ionization energy of hydrogen. [Hint: According to Coulomb's law, the energy between two charges $Q_{1}$ and $Q_{2}$ separated by distance $r$ is proportional to $\left.\left(Q_{1} Q_{2} / r\right) .\right]$

Lottie Adams

Numerade Educator

Problem 143

As mentioned in the Chemistry in Action essay "Chemical Fertilizers" in Section 3.10 , ammonium nitrate $\left(\mathrm{NH}_{4} \mathrm{NO}_{3}\right)$ is the most important nitrogencontaining fertilizer in the world. Describe how you would prepare this compound, given only air and water as the starting materials. You may have any device at your disposal for this task.

Susan Hallstrom

Susan Hallstrom

Numerade Educator

Problem 144

One way to estimate the effective charge $\left(Z_{\text {eff }}\right)$ of a many-electron atom is to use the equation $I E_{1}=$ $(1312 \mathrm{~kJ} / \mathrm{mol})\left(\mathrm{Z}_{\text {eff }}^{2} / n^{2}\right),$ where $I E_{1}$ is the first ionization energy and $n$ is the principal quantum number of the shell in which the electron resides. Use this equation to calculate the effective charges of $\mathrm{Li}, \mathrm{Na}$, and $\mathrm{K}$. Also calculate $Z_{\text {eff }} / n$ for each metal. Comment on your results.

David Collins

Numerade Educator

Problem 145

To prevent the formation of oxides, peroxides, and superoxides, alkali metals are sometimes stored in an inert atmosphere. Which of the following gases should not be used for lithium: $\mathrm{Ne}, \mathrm{Ar}, \mathrm{N}_{2}, \mathrm{Kr} ?$ Explain. (Hint: As mentioned in the chapter, Li and Mg exhibit a diagonal relationship. Compare the common compounds of these two elements.)

Supratim Pal

Numerade Educator

Problem 146

Describe the biological role of the elements in the human body shown in the following periodic table.

Emily Himsel

Numerade Educator

Problem 147

Recent theoretical calculations suggest that astatine may be a monoatomic metal rather than a diatomic molecule like the other halogens. (a) Rationalize this prediction based on astatine's position in the periodic table. (b) The energy required to remove an electron from one At atom was determined by laser ionization to be $9.3175 \mathrm{eV}$. Given that $1 \mathrm{eV}=1.602$ $\times 10^{-19} \mathrm{~J},$ calculate the first ionization energy of astatine in $\mathrm{kJ} / \mathrm{mol} .$ (c) Comment on whether or not the following first ionization energies support your answer to part (a): $\mathrm{Pb}, 715.6 \mathrm{~kJ} / \mathrm{mol} ; \mathrm{Bi}, 702.9 \mathrm{~kJ} / \mathrm{mol} ;$
$\mathrm{Po}, 811.8 \mathrm{~kJ} / \mathrm{mol} ; \mathrm{Rn}, 1037 \mathrm{~kJ} / \mathrm{mol}$

Lottie Adams

Numerade Educator

Problem 148

Consider the first 18 elements from hydrogen to argon. Would you expect the atoms of half of them to be diamagnetic and half of them to be paramagnetic? Explain.

Anand Jangid

Numerade Educator

Problem 149

Compare the work function for cesium ( $206 \mathrm{~kJ} / \mathrm{mol}$ ) with its first ionization energy ( $376 \mathrm{~kJ} / \mathrm{mol}$ ). Explain the difference.

Nicole Smina

Numerade Educator

Problem 150

The only confirmed compound of radon is radon difluoride, $\operatorname{RnF}_{2}$. One reason that it is difficult to study the chemistry of radon is that all isotopes of radon are radioactive so it is dangerous to handle the substance. Can you suggest another reason why there are so few known radon compounds? (Hint:
Radioactive decays are exothermic processes.)

Anand Jangid

Numerade Educator

Problem 151

Arsenic (As) is not an essential element for the human body. (a) Based on its position in the periodic table, suggest a reason for its toxicity. (b) When arsenic enters a person's body, it quickly shows up in the follicle of the growing hair. This action has enabled detectives to solve many murder mysteries by analyzing a victim's hair. Where else might one look for the accumulation of the element if arsenic poisoning is suspected?

Anand Jangid

Numerade Educator

Problem 152

The boiling points of neon and krypton are $-245.9^{\circ} \mathrm{C}$ and $-152.9^{\circ} \mathrm{C},$ respectively. Using these data, estimate the boiling point of argon.

Lottie Adams

Numerade Educator

Problem 153

Using the following boiling-point data, estimate the boiling point of francium:
$$
\begin{array}{l|l|l|l|l|l|l}
\text { Metal } & \mathrm{Li} & \mathrm{Na} & \mathrm{K} & \mathrm{Rb} & \mathrm{Cs} & \mathrm{Fr} \\
\hline \text { B.p. }\left({ }^{\circ} \mathrm{C}\right) & 1347 & 882.9 & 774 & 688 & 678.4 & ?
\end{array}
$$

David Collins

Numerade Educator

Problem 154

The energy gap between the $6 s$ and $5 d$ levels in gold is $4.32 \times 10^{-19} \mathrm{~J}$. Based on this information, predict the perceived color of gold vapor. (Hint: You need to be familiar with the notion of complementary color; see Figure $23.18 .)$

Nicole Smina

Numerade Educator

Problem 155

Calculate the volume of 1 mole of $\mathrm{K}$ atoms (see Figure 8.5 ) and compare the result by using the density of $\mathrm{K}\left(0.856 \mathrm{~g} / \mathrm{cm}^{3}\right) .$ Account for the difference.

Cheryl Glor

Numerade Educator