Problem 1

MAIN Idea Contrast the methods used by the Greek philosophers and Dalton

to study the atom.

Anna M.

Numerade Educator

Problem 4

Explain how Dalton's theory of the atom and the conservation of mass are

related.

Keenan M.

University of Miami

Problem 5

Apply Six atoms of Element A combine with 15 atoms of Element B to produce

six compound particles. How many atoms of Elements A and B does each particle

contain? Are all of the atoms used to form compounds?

Anna M.

Numerade Educator

Problem 6

Design a concept map that compares and contrasts the atomic ideas proposed

by Democritus and John Dalton.

Keenan M.

University of Miami

Problem 7

MAIN Idea Describe the structure of a typical atom. Identify where each

subatomic particle is located.

Anna M.

Numerade Educator

Problem 8

Compare and contrast Thomson's plum pudding atomic model with

Rutherford's nuclear atomic model.

Keenan M.

University of Miami

Problem 9

Evaluate the experiments that led to the conclusion that electrons are

negatively charged particles found in all matter.

Anna M.

Numerade Educator

Problem 10

Compare the relative charge and mass of each of the subatomic particles.

Keenan M.

University of Miami

Problem 11

Calculate What is the difference expressed in kilograms between the mass of

a proton and the mass of an electron?

Anna M.

Numerade Educator

Problem 12

How many protons and electrons are in each atom?

a. radon $\quad$ b. magnesium

Keenan M.

University of Miami

Problem 13

An atom of an element contains 66 electrons. Which element is it?

Anna M.

Numerade Educator

Problem 14

An atom of an element contains 14 protons. Which element is it?

Keenan M.

University of Miami

Problem 15

Challenge Do the atoms shown in the figure to the right have

the same atomic number?

Check back soon!

Problem 16

Determine the number of protons, electrons, and neutrons for isotopes b.-f. in the table above

Name each isotope, and write its symbol.

Keenan M.

University of Miami

Problem 17

Challenge An atom has a mass number of 55. Its number of neutrons is the sum of its

atomic number and five. How many protons, neutrons, and electrons does this atom have?

What is the identity of this atom?

Anna M.

Numerade Educator

Problem 18

Boron (B) has two naturally occurring isotopes: boron-10 (abundance $=19.8 \%$

mass $=10.013$ amu) and boron-11 (abundance $=80.2 \%,$ mass $=11.009$ amu).

Calculate the atomic mass of boron.

Keenan M.

University of Miami

Problem 19

Challenge Nitrogen has two naturally occurring isotopes, $\mathrm{N}-14$ and $\mathrm{N}-15 .$ Its atomic

mass is 14.007 . Which isotope is more abundant? Explain your answer.

Anna M.

Numerade Educator

Problem 21

Recall Which subatomic particle identifies an atom as that of a particular

element?

Anna M.

Numerade Educator

Problem 22

Explain how the existence of isotopes is related to the fact that atomic masses

are not whole numbers.

Keenan M.

University of Miami

Problem 23

Calculate Copper has two isotopes: $C u-63$ (abundance $=69.2 \%$

mass $=62.930$ amul and $\mathrm{Cu}-65$ (abundance $=30.8 \%,$ mass $=64.928$ amu).

Calculate the atomic mass of copper.

Anna M.

Numerade Educator

Problem 24

Calculate Three magnesium isotopes have atomic masses and relative abun-

dances of 23.985 amu $(79.99 \%), 24.986$ amu $(10.00 \%),$ and 25.982$(11.01 \%) .$

Calculate the atomic mass of magnesium.

Keenan M.

University of Miami

Problem 26

State what quantities are conserved when balancing a nuclear reaction.

Keenan M.

University of Miami

Problem 27

Classify each of the following as a chemical reaction, a nuclear reaction,

or neither

\begin{equation}

\begin{array}{l}{\text { a. Thorium emits a beta particle. }} \\ {\text { b. Two atoms share electrons to form a bond. }} \\ {\text { c. A sample of pure sulfur emits heat energy as it slowly cools. }} \\ {\text { d. A piece of iron rusts. }}\end{array}

\end{equation}

Anna M.

Numerade Educator

Problem 28

Calculate How much heavier is an alpha particle than an electron?

Keenan M.

University of Miami

Problem 29

Create a table showing how each type of radiation affects the atomic number

and the mass number of an atom.

Anna M.

Numerade Educator

Problem 30

Who originally proposed the concept that matter is

composed of tiny, indivisible particles?

Keenan M.

University of Miami

Problem 31

Whose work is credited with being the beginning of

modern atomic theory?

Anna M.

Numerade Educator

Problem 32

Distinguish between Democritus's ideas and Dalton's

atomic theory.

Keenan M.

University of Miami

Problem 33

Ideas and Scientific Methods Was Democritus's proposal of the existence of atoms based on scientific methods or ideas? Explain.

Anna M.

Numerade Educator

Problem 34

Explain why Democritus was unable to experimentally

verify his ideas

Keenan M.

University of Miami

Problem 36

State the main points of Dalton's atomic theory using

your own words. Which parts of Dalton's theory were

later found to be erronous? Explain why.

Keenan M.

University of Miami

Problem 37

Conservation of Mass Explain how Dalton's atomic

theory offered a convincing explanation of the observation that mass is conserved in chemical reactions.

Anna M.

Numerade Educator

Problem 39

What particles are found in the nucleus of an atom?

What is the charge of the nucleus?

Anna M.

Numerade Educator

Problem 40

How was the overall charge distributed in the plum

pudding model?

Keenan M.

University of Miami

Problem 41

How did the charge distribution in the plum pudding

model affect alpha particles passing through an atom?

Anna M.

Numerade Educator

Problem 43

Arrange the following subatomic particles in order of

increasing mass: neutron, electron, and proton.

Anna M.

Numerade Educator

Problem 47

If you had a balance that could determine the mass of a

proton, how many clectrons would you need to weigh

on the same balance to measure the same mass as that of

a single proton?

Anna M.

Numerade Educator

Problem 48

Cathode-Ray Tubes Which subatomic particle was dis-

covered by researchers working with cathode-ray tubes?

Keenan M.

University of Miami

Problem 49

What experimental results led to the conclusion that

electrons were part of all forms of matter?

Anna M.

Numerade Educator

Problem 50

Cathode Ray Use the elements labeled in Figure 4.23

to explain the direction of a cathode ray inside a

cathode-ray tube.

Keenan M.

University of Miami

Problem 52

Particle Deflection What caused the deflection of the

alpha particles in Rutherford's gold foil experiment?

Keenan M.

University of Miami

Problem 53

Charge of Cathode Rays How was an electric field

used to determine the charge of a cathode ray?

Anna M.

Numerade Educator

Problem 54

Explain what keeps the electrons confined in the space

surrounding the nucleus.

Keenan M.

University of Miami

Problem 56

Visualizing Atoms What technique can be used to

visualize individual atoms?

Keenan M.

University of Miami

Problem 57

What are the strengths and weaknesses of Rutherford's

nuclear model of the atom?

Check back soon!

Problem 58

How do isotopes of a given element differ? How are they

similar?

Keenan M.

University of Miami

Problem 59

How is an atom's atomic number related to its number of

protons? To its number of electrons?

Anna M.

Numerade Educator

Problem 60

How is the mass number related to the number of protons and neutrons an atom has?

Keenan M.

University of Miami

Problem 61

How can you determine the number of neutrons in an

atom if its mass number and its atomic number are

known.

Anna M.

Numerade Educator

Problem 62

What do the superscript and subscript in the notation

$\stackrel{40}{19} \mathrm{K}$ represent?

Keenan M.

University of Miami

Problem 63

Standard Units Define the atomic mass unit. What

were the benefits of developing the atomic mass unit as a

standard unit of mass?

Anna M.

Numerade Educator

Problem 64

Isotopes Are the following elements isotopes of each

other? Explain.

$$

_{12}^{24} \mathrm{Mg}_{12}^{25} \mathrm{Mg}_{12}^{26} \mathrm{Mg}

$$

Keenan M.

University of Miami

Problem 65

Does the existence of isotopes contradict part of Dalton's

original atomic theory? Explain.

Anna M.

Numerade Educator

Problem 66

How many protons and electrons are contained in an

atom of element 44 ?

Keenan M.

University of Miami

Problem 67

Carbon A carbon atom has a mass number of 12 and

an atomic number of $6 .$ How many neutrons does it

have?

Anna M.

Numerade Educator

Problem 68

Mercury An isotope of mercury has 80 protons and 120

neutrons. What is the mass number of this isotope?

Keenan M.

University of Miami

Problem 69

Xenon An isotope of xenon has an atomic number of

54 and contains 77 neutrons. What is the xenon isotope's

Anna M.

Numerade Educator

Problem 73

How many electrons, protons, and neutrons are

contained in each atom?

\begin{equation}

\begin{array}{ll}{\text { a. }_{55}^{132} \mathrm{Cs}} & {\text { c. }_{69}^{163} \mathrm{Tm}} \\ {\text { b. }_{27}^{59} \mathrm{Co}} & {\text { d. }_{30}^{70} \mathrm{Zn}}\end{array}

\end{equation}

Anna M.

Numerade Educator

Problem 74

How many electrons, protons, and neutrons are

contained in each atom?

\begin{equation}

\begin{array}{ll}{\text { a. gallium- } 69} & {\text { c. titanium- } 48} \\ {\text { b. fluorine- } 23} & {\text { d. } \text { tantalum }-181}\end{array}

\end{equation}

Keenan M.

University of Miami

Problem 75

For each chemical symbol, determine the number of

protons and electrons an atom of the element contains.

\begin{equation}

\begin{array}{ll}{\text { a. } V} & {\text { c. Ir }} \\ {\text { b. Mn }} & {\text { d. } S}\end{array}

\end{equation}

Anna M.

Numerade Educator

Problem 76

Gallium, which has an atomic mass of 69.723 amu, has

two naturally occurring isotopes, Ga- 69 and Ga- $71 .$

Which isotope occurs in greater abundance? Explain.

Keenan M.

University of Miami

Problem 77

Atomic Mass of Silver Silver has two isotopes:

$\stackrel{107}{47} \mathrm{Ag}$ which has a mass of 106.905 amu and a percent

abundance of 52.00$\%$, and 47

$\stackrel{109}{47} \mathrm{Ag}$, which has a mass of

108.905 amu and an percent abundance of 48.00$\%$

What is the atomic mass of silver?

Anna M.

Numerade Educator

Problem 78

Data for chromium's four naturally occuring isotopes are

provided in Table 4.7 . Calculate chromium's atomic mass.

Keenan M.

University of Miami

Problem 83

Write the symbols used to denote alpha, beta, and

gamma radiation and give their mass and charge.

Anna M.

Numerade Educator

Problem 84

What type of reaction involves changes in the nucleus of

an atom?

Keenan M.

University of Miami

Problem 85

Radioactive Emissions What change in mass number

occurs when a radioactive atom emits an alpha particle?

A beta particle? A gamma particle?

Anna M.

Numerade Educator

Problem 86

What is the primary factor that determines whether an

nucleus is stable or unstable?

Keenan M.

University of Miami

Problem 87

Explain how energy loss and nuclear stability are related

to radioactive decay

Anna M.

Numerade Educator

Problem 88

Explain what must occur before a radioactive atom stops

to undergo further radioactive decay

Keenan M.

University of Miami

Problem 89

Boron-10 emits alpha particles and cesium-137 emits

beta particles. Write balanced nuclear reactions for each

radioactive decay.

Check back soon!

Problem 90

Determine what was wrong with Dalton's theory and

provide the most recent version of the atomic structure.

Keenan M.

University of Miami

Problem 91

Cathode-Ray Tube Describe a cathode-ray tube and

how it operates.

Anna M.

Numerade Educator

Problem 92

Subatomic Particles Explain how J. J. Thomson's determination of the charge-to-mass ratio of the electron led

to the conclusion that atoms were composed of subatomic particles.

Keenan M.

University of Miami

Problem 93

Gold Foil Experiment How did the actual results of

Rutherford's gold foil experiment differ from the results

he expected?

Anna M.

Numerade Educator

Problem 94

If a nucleus contains 12 protons, how many electrons are

in the neutral atom? Explain.

Keenan M.

University of Miami

Problem 95

An atom's nucleus has 92 protons and its mass number is

235. How many neutrons are in the nucleus? What is the

name of the atom?

Anna M.

Numerade Educator

Problem 97

Approximately how many times greater is the diameter

of an atom than the diameter of its nucleus? Knowing

that most of an atom's mass is contained in the nucleus,

what can you conclude about the density of the nucleus?

Anna M.

Numerade Educator

Problem 98

Is the charge of a nucleus positive, negative, or zero?

The charge of an atom?

Keenan M.

University of Miami

Problem 99

Why are electrons in a cathode-ray tube deflected by

electric fields?

Anna M.

Numerade Educator

Problem 100

What was Henry Moseley's contribution to the modern

understanding of the atom?

Keenan M.

University of Miami

Problem 101

What is the mass number of potassium- 39$?$ What is the

isotope's charge?

Anna M.

Numerade Educator

Problem 102

Boron-10 and boron-11 are the naturally occurring isotopes of elemental boron. If boron has an atomic mass of

10.81 amu, which isotope occurs in greater abundance?

Keenan M.

University of Miami

Problem 103

Semiconductors Silicon is important to the semiconductor manufacturing industry. The three naturally

occuring isotopes of silicon are silicon-28, silicon-29,

and silicon-30. Write the symbol for each.

Anna M.

Numerade Educator

Problem 104

Titanium Use Table 4.9 to calculate the atomic mass of

titanium.

Keenan M.

University of Miami

Problem 105

Describe how each type of radiation affects an atom's

atomic number and mass number.

Anna M.

Numerade Educator

Problem 106

Relative Abundances Magnesium constitutes about 2$\%$

of Earth's crust and has three naturally occurring isotopes. Suppose you analyze a mineral and determine

that it contains the three isotopes in the following proportions: Mg- 24 (abundance = $79 \% ), \mathrm{Mg}-25$ (abundance $=10 \% ),$ and $\mathrm{Mg}-26$ (abundance = 11 $\%$ ). If your

friend analyzes a different mineral containing magnesium, do you expect her to obtain the same relative

abundances for each magnesium isotope? Explain your

reasoning.

Keenan M.

University of Miami

Problem 107

Radiation Identify the two types of radiation shown in

Figure 4.24. Explain your reasoning

Anna M.

Numerade Educator

Problem 108

Formulate How were scientific methods used to determine the model of the atom? Why is the model considered a theory?

Keenan M.

University of Miami

Problem 109

Discuss What experiment led to the dispute of J. J.

Thomson's plum pudding atomic model? Explain your

answer.

Anna M.

Numerade Educator

Problem 110

Apply Which is greater, the number of compounds or

the number of elements? The number of elements or the

number of isotopes? Explain.

Keenan M.

University of Miami

Problem 111

Analyze An element has three naturally occurring iso-

topes. What other information must you know in order

to calculate the element's atomic mass?

Anna M.

Numerade Educator

Problem 112

Apply If atoms are primarily composed of empty space,

explain why you cannot pass your hand through a solid

object.

Keenan M.

University of Miami

Problem 113

Formulate Sketch a modern atomic model of a typical

atom and identify where each type of subatomic particle

would be located.

Anna M.

Numerade Educator

Problem 114

Apply Indium has two naturally occurring isotopes

and an atomic mass of 114.818 amu. In $-113$ has a mass

of 112.904 amu and an abundance of 4.3$\%$ . What is

the identity and percent abundance of indium's other

isotope?

Keenan M.

University of Miami

Problem 115

Infer Sulfur's average atomic mass is close to the whole

number $32 .$ Chlorine's average atomic mass is 35.453 ,

which is not a whole number. Suggest a possible reason

for this difference.

Anna M.

Numerade Educator

Problem 116

Magnesium Isotopes Compute the mass number,

$X,$ of the third isotope of magnesium given that the

respective abundances of the naturally occurring isotopes are: $79.0 \%, 10 \%,$ and 11$\%$ for

$_{12}^{24} \mathrm{Mg}_{12}^{25} \mathrm{Mg}_{12}^{X} \mathrm{Mg}.$ The relative atomic mass of magnesium is 24.305 amu.

Keenan M.

University of Miami

Problem 117

How is a qualitative observation different from a quantitative observation? Give an example of each. (Chapter 1$)$

Anna M.

Numerade Educator

Problem 118

A 1.0 -cm' block of gold can be flattened to a thin sheet

that averages $3.0 \times 10^{-8} \mathrm{cm}$ thick. What is the area ( in cm 2 ) of the flattened gold sheet? (Chapter 2)

Keenan M.

University of Miami

Problem 119

A piece of paper has area of 603 $\mathrm{cm}^{2} .$ How many

sheets of paper would the sheet of gold mentioned in

problem 118 cover? (Chapter 2$)$

Check back soon!

Problem 120

Classify each mixture as heterogeneous or homogeneous. (Chapter 3)

\begin{equation}

\begin{array}{l}{\text { a. salt water }} \\ {\text { b. vegetable soup }} \\ {\text { c. } 14-\mathrm{K} \text { gold }} \\ {\text { d. concrete }}\end{array}

\end{equation}

Keenan M.

University of Miami

Problem 121

Determine whether each change is physical or chemical.

(Chapter 3$)$

\begin{equation}

\begin{array}{l}{\text { a. Water boils. }} \\ {\text { b. A match burns. }} \\ {\text { c. Sugar dissolves in water. }} \\ {\text { d. Sodium reacts with water. }} \\ {\text { e. Ice cream melts. }}\end{array}

\end{equation}

Anna M.

Numerade Educator

Problem 122

Television and Computer Screens Describe how

cathode rays are used to generate television and computer monitor images.

Keenan M.

University of Miami

Problem 123

The Standard Model The standard model of particle

physics describes all of the known building blocks of

matter. Research the particles included in the standard model. Write a short report describing the

known particles and those thought to exist but not yet

detected experimentally.

Check back soon!

Problem 124

STM Individual atoms can be seen using a sophisti-

cated device known as a scanning tunneling micro-

scope. Write a short report on how the scanning

tunneling microscope works and create a gallery of

this microscope's images from sources such as books,

magazines, and the Internet.

Keenan M.

University of Miami

Problem 126

Compute the number of protons and neutrons for

each zirconium isotope.

Keenan M.

University of Miami

Problem 127

Does the number of protons or neutrons remain the

same for all isotopes? Explain.

Anna M.

Numerade Educator

Problem 128

Based on the relative abundances of each isotope,

predict to which isotope's mass the average atomic

mass of zirconium is going to be closest.

Keenan M.

University of Miami