Chemistry

Kenneth W. Whitten, Raymond E. Davis, Larry Peck

Chapter 4

The Structure of Atoms - all with Video Answers

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Chapter Questions

Problem 1

List the three fundamental particles of atoms, and indicate the mass and charge associated with each.

Nicole Smina

Nicole Smina

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Problem 2

In the oil-drop experiment, how did Millikan know that none of the oil droplets he observed were ones that had a deficiency of electrons rather than an excess?

Ronald Prasad

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Problem 3

How many electrons carry a total charge of 1.00 coulomb?

Nicole Smina

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Problem 4

(a) How do we know that canal rays have charges opposite in sign to cathode rays? What are canal rays?
(b) Why are cathode rays from all samples of gases identical, whereas canal rays are not?

Jennifer Hudspeth

Jennifer Hudspeth

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Problem 5

The following data are measurements of the charges on oil droplets using an apparatus similar to that used by Millikan:
$$
\begin{array}{ll}
13.458 \times 10^{-19} \mathrm{C} & 15.373 \times 10^{-19} \mathrm{C} \\
17.303 \times 10^{-19} \mathrm{C} & 15.378 \times 10^{-19} \mathrm{C} \\
17.308 \times 10^{-19} \mathrm{C} & 28.844 \times 10^{-19} \mathrm{C} \\
11.545 \times 10^{-19} \mathrm{C} & 19.214 \times 10^{-19} \mathrm{C}
\end{array}
$$
Each should be a whole-number ratio of some fundamental charge. Using these data, determine the largest possible value of the fundamental charge.

Ronald Prasad

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Problem 6

Suppose we discover a new positively charged particle, which we call the "whizatron." We want to determine its charge. (a) What modifications would we have to make to the Millikan oil-drop apparatus to carry out the corresponding experiment on whizatrons? (b) In such an experiment, we observe the following charges on five different droplets:
$$
\begin{array}{ll}
4.88 \times 10^{-19} \mathrm{C} & 8.53 \times 10^{-19} \mathrm{C} \\
6.10 \times 10^{-19} \mathrm{C} & 7.32 \times 10^{-19} \mathrm{C} \\
2.44 \times 10^{-19} \mathrm{C} &
\end{array}
$$
What is the largest possible value of the charge on the whizatron?

Jennifer Hudspeth

Jennifer Hudspeth

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Problem 7

Outline Rutherford's contribution to understanding the nature of atoms.

Jennifer Hudspeth

Jennifer Hudspeth

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Problem 8

Why was Rutherford so surprised that some of the $\alpha$ -particles were scattered backward in the gold foil experiment?

Jennifer Hudspeth

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Problem 9

Summarize Moseley's contribution to our knowledge of the structure of atoms.

Jennifer Hudspeth

Jennifer Hudspeth

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Problem 10

The approximate radius of a hydrogen atom is $0.0529 \mathrm{nm},$ and that of a proton is $1.5 \times 10^{-15} \mathrm{~m}$ Assuming both the hydrogen atom and the proton to be spherical, calculate the fraction of the space in an atom of hydrogen that is occupied by the nucleus. $V=(4 / 3) \pi r^{3}$ for a sphere.

Jennifer Hudspeth

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Problem 11

The approximate radius of a neutron is $1.5 \times 10^{-15} \mathrm{~m}$ and the mass is $1.675 \times 10^{-27} \mathrm{~kg}$. Calculate the density of a neutron. $V=(4 / 3) \pi r^{3}$ for a sphere.

Jennifer Hudspeth

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Problem 12

Arrange the following in order of increasing ratio of charge to mass: ${ }^{12} \mathrm{C}^{+},{ }^{12} \mathrm{C}^{2+},{ }^{14} \mathrm{~N}^{+},{ }^{14} \mathrm{~N}^{2+}$.

Nicole Smina

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Problem 13

A Refer to Exercise 12. Suppose all of these high-energy ions are present in a mass spectrometer. For which one will its path be changed (a) the most and (b) the least by increasing the external magnetic field? Which of the ions would take (c) the longest time and (d) the shortest time to travel a given distance in a time-of-flight mass spectrometer?

Ronald Prasad

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Problem 14

Estimate the percentage of the total mass of a ${ }^{58} \mathrm{Ni}$ atom that is due to (a) electrons, (b) protons, and (c) neutrons by assuming that the mass of the atom is simply the sum of the masses of the appropriate numbers of subatomic particles.

Nicole Smina

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Problem 15

(a) How are isotopic abundances determined experimentally? (b) How do the isotopes of a given element differ?

Jennifer Hudspeth

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Problem 16

Clearly define and provide examples that illustrate the meaning of each: (a) atomic number; (b) isotope; (c) mass number; (d) nuclear charge.

Nicole Smina

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Problem 17

Write the composition of one atom of each of the three isotopes of silicon: ${ }^{28} \mathrm{Si},{ }^{29} \mathrm{Si},{ }^{30} \mathrm{Si}$.

Nicole Smina

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Problem 18

Write the composition of one atom of each of the four isotopes of strontium: ${ }^{84} \mathrm{Sr},{ }^{86} \mathrm{Sr},{ }^{87} \mathrm{Sr},{ }^{88} \mathrm{Sr}$.

Nicole Smina

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Problem 19

Complete Chart $\mathrm{A}$ on the next page for neutral atoms.

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Problem 20

Complete Chart $\mathrm{B}$ on the next page for neutral atoms.

Jennifer Hudspeth

Jennifer Hudspeth

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Problem 21

Prior to $1962,$ the atomic weight scale was based on the assignment of an atomic weight of exactly 16 amu to the naturally occurring mixture of oxygen. The atomic weight of nickel is 58.6934 amu on the carbon-12 scale. What would it have been on the older scale?

Ronald Prasad

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Problem 22

Determine the number of protons, neutrons, and electrons in each of the following species: (a) ${ }^{24} \mathrm{Mg}$; (b) $^{51} \mathrm{~V}$ (c) ${ }^{91} \mathrm{Zr}$ (d) ${ }^{27} \mathrm{Al} ;$ (e) $^{65} \mathrm{Zn}^{2+}$ (f) $^{108} \mathrm{Ag}^{+}$

Nicole Smina

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Problem 23

Determine the number of protons, neutrons, and electrons in each of the following species: (a) ${ }^{52} \mathrm{Cr}$; (b) ${ }^{112} \mathrm{Cd}$ (c) ${ }^{137} \mathrm{Ba}^{2+}$ (d) ${ }^{63} \mathrm{Cu}^{+}$ (e) ${ }^{56} \mathrm{Fe}^{2+} ;(\mathrm{f}){ }^{55} \mathrm{Fe}^{3+}$

Nicole Smina

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Problem 24

What is the symbol of the species composed of each of the following sets of subatomic particles?
(a) $24 p, 28 n, 24 e$
(b) $20 p, 20 n, 20 e$
(c) $33 p, 42 n, 33 e$
(d) $53 p, 74 n, 53 e$.

Jennifer Hudspeth

Jennifer Hudspeth

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Problem 25

What is the symbol of the species composed of each of the following sets of subatomic particles? (a) $94 p, 150 n$, $94 e ;$ (b) $79 p, 118 n, 76 e ;$ (c) $34 p, 45 n, 34 e ;$ (d) $56 p, 80 n, 56 e$.

Jennifer Hudspeth

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Problem 26

The listed atomic weight of gallium is 69.723 amu. Gallium has two stable isotopes, both of which are used in nuclear medicine. These two stable isotopes have the following masses: ${ }^{69} \mathrm{Ga}, 68.925580 ;{ }^{71} \mathrm{Ga}, 70.9247005 .$ Calculate the percent of each isotope in naturally occurring gallium.

Jennifer Hudspeth

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Problem 27

The atomic weight of rubidium is 85.4678 amu. The two naturally occurring isotopes of rubidium have the following masses: ${ }^{85} \mathrm{Rb}, 84.9118 \mathrm{amu} ;{ }^{87} \mathrm{Rb}, 86.9092$ amu. Calculate the percent of each isotope in naturally occurring rubidium.

Nicole Smina

Numerade Educator

Problem 28

Strontium has four isotopes with the following masses: $83.9134 \mathrm{amu}(0.56 \%), 85.9094 \mathrm{amu}(9.86 \%), 86.9089 \mathrm{amu}$ (7.00\%), and $87.9056(82.58 \%) .$ Calculate the atomic mass of strontium.

Jennifer Hudspeth

Jennifer Hudspeth

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Problem 29

What is the atomic weight of a hypothetical element that consists of the following isotopes in the indicated relative abundances?
$$
\begin{array}{ccc}
\text { Isotope } & \begin{array}{c}
\text { Isotopic } \\
\text { Mass (amu) }
\end{array} & \begin{array}{c}
\text { \% Natural } \\
\text { Abundance }
\end{array} \\
\hline 1 & 94.9 & 12.4 \\
2 & 95.9 & 73.6 \\
3 & 97.9 & 14.0 \\
\hline
\end{array}
$$

Nicole Smina

Numerade Educator

Problem 30

Naturally occurring iron consists of four isotopes with the abundances indicated here. From the masses and relative abundances of these isotopes, calculate the atomic weight of naturally occurring iron.
$$
\begin{array}{ccc}
\text { Isotope } & \begin{array}{c}
\text { Isotopic } \\
\text { Mass (amu) }
\end{array} & \begin{array}{c}
\text { \% Natural } \\
\text { Abundance }
\end{array} \\
\hline{ }^{54} \mathrm{Fe} & 53.9396 & 5.82 \\
{ }^{56} \mathrm{Fe} & 55.9349 & 91.66 \\
{ }^{57} \mathrm{Fe} & 56.9354 & 2.19 \\
{ }^{58} \mathrm{Fe} & 57.9333 & 0.33 \\
\hline
\end{array}
$$

Jennifer Hudspeth

Jennifer Hudspeth

Numerade Educator

Problem 31

Calculate the atomic weight of nickel from the following information.
$$
\begin{array}{lcc}
\text { Isotope } & \begin{array}{c}
\text { Isotopic } \\
\text { Mass (amu) }
\end{array} & \begin{array}{c}
\text { \% Natural } \\
\text { Abundance }
\end{array} \\
\hline{ }^{58} \mathrm{Ni} & 57.9353 & 68.08 \\
{ }^{60} \mathrm{Ni} & 59.9308 & 26.22 \\
{ }^{61} \mathrm{Ni} & 60.9311 & 1.14 \\
{ }^{62} \mathrm{Ni} & 61.9283 & 3.63 \\
{ }^{64} \mathrm{Ni} & 63.9280 & 0.93 \\
\hline
\end{array}
$$

Jennifer Hudspeth

Jennifer Hudspeth

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Problem 32

The atomic weight of copper is 63.546 amu. The two naturally occurring isotopes of copper have the following masses: ${ }^{63} \mathrm{Cu}, 62.9298 \mathrm{amu} ;{ }^{65} \mathrm{Cu}, 64.9278$ amu. Calculate the percent of ${ }^{63} \mathrm{Cu}$ in naturally occurring copper.

Jennifer Hudspeth

Jennifer Hudspeth

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Problem 33

Silver consists of two naturally occurring isotopes: ${ }^{107} \mathrm{Ag}$, which has a mass of $106.90509 \mathrm{amu}$, and ${ }^{109} \mathrm{Ag}$, which has a mass of 108.9047 amu. The atomic weight of silver is 107.8682 amu. Determine the percent abundance of each isotope in naturally occurring silver.

Jennifer Hudspeth

Jennifer Hudspeth

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Problem 34

Refer to Table $4-3$ only and calculate the atomic weights of oxygen and chlorine. Do your answers agree with the atomic weights given in that table?

Jennifer Hudspeth

Jennifer Hudspeth

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Problem 35

The following is a mass spectrum of the $1+$ charged ions of an element. Calculate the atomic weight of the element. What is the element?

Jennifer Hudspeth

Jennifer Hudspeth

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Problem 36

Suppose you measure the mass spectrum of the $1+$ charged ions of germanium, atomic weight 72.61 amu. Unfortunately, the mass spectrometer malfunctions at the beginning and again at the end of your experiment. You obtain only the following spectrum, which may or may not be complete. From the information given here, can you tell whether one of the germanium isotopes is missing? If one is missing, at which end of the plot should it appear?

Jennifer Hudspeth

Jennifer Hudspeth

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Problem 37

Calculate the atomic weight of silicon using the following data for the percent natural abundance and mass of each isotope: $92.23 \%{ }^{28} \mathrm{Si}(27.9769 \mathrm{amu}) ; 4.67 \%{ }^{29} \mathrm{Si}(28.9765$ $\mathrm{amu}) ; 3.10 \%{ }^{30} \mathrm{Si}(29.9738 \mathrm{amu})$

Jennifer Hudspeth

Jennifer Hudspeth

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Problem 38

Calculate the atomic weight of chromium using the following data for the percent natural abundance and mass of each isotope: $4.35 \%{ }^{50} \mathrm{Cr}(49.9461 \mathrm{amu}) ; 83.79 \%{ }^{52} \mathrm{Cr}$ $(51.9405 \mathrm{amu}) ; 9.50 \%{ }^{53} \mathrm{Cr}(52.9406 \mathrm{amu}) ; 2.36 \%{ }^{54} \mathrm{Cr}$ $(53.9389 \mathrm{amu})$

Jennifer Hudspeth

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Problem 39

State the periodic law. What does it mean?

Nicole Smina

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Problem 40

What was Mendeleev's contribution to the construction of the modern periodic table?

Nicole Smina

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Problem 41

Consult a handbook of chemistry or a suitable website, and look up melting points of the elements of Periods 2 and $3 .$ Show that melting point is a property that varies periodically for these elements.

Ronald Prasad

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Problem 42

Mendeleev's periodic table was based on increasing atomic weight. Argon has a higher atomic weight than potassium, yet in the modern table argon appears before potassium. Explain how this can be.

Nicole Smina

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Problem 43

Estimate the density of antimony from the following densities $\left(\mathrm{g} / \mathrm{cm}^{3}\right): \mathrm{As}, 5.72 ; \mathrm{Bi}, 9.8 ; \mathrm{Sn}, 7.30 ; \mathrm{Te}, 6.24 .$ Show how you arrived at your answer. Using a reference other than your textbook, look up the density of antimony. How does your predicted value compare with the reported value?

Jennifer Hudspeth

Jennifer Hudspeth

Numerade Educator

Problem 44

Estimate the density of selenium from the following densities $\left(\mathrm{g} / \mathrm{cm}^{3}\right): \mathrm{S}, 2.07 ; \mathrm{Te}, 6.24 ; \mathrm{As}, 5.72 ; \mathrm{Br}, 3.12$ Show how you arrived at your answer. Using a reference other than your textbook, look up the density of selenium. How does your predicted value compare with the reported value?

Jennifer Hudspeth

Jennifer Hudspeth

Numerade Educator

Problem 45

Estimate the specific heat of antimony from the following specific heats $\left(\mathrm{J} / \mathrm{g} \cdot{ }^{\circ} \mathrm{C}\right): \mathrm{As}, 0.34 ; \mathrm{Bi}, 0.14 ; \mathrm{Sn}, 0.23 ; \mathrm{Te}, 0.20 .$ Show how you arrived at your answer.

Jennifer Hudspeth

Jennifer Hudspeth

Numerade Educator

Problem 46

Given the following melting points in ${ }^{\circ} \mathrm{C}$, estimate the value for $\mathrm{CBr}_{4}: \mathrm{CF}_{4},-184 ; \mathrm{CCl}_{4},-23 ; \mathrm{CI}_{4}, 171$ (decomposes). Using a reference other than your textbook, look up the melting point of $\mathrm{CBr}_{4}$. How does your predicted value compare with the reported value?

Jennifer Hudspeth

Jennifer Hudspeth

Numerade Educator

Problem 47

Calcium and magnesium form the following compounds: $\mathrm{CaCl}_{2}, \mathrm{MgCl}_{2}, \mathrm{CaO}, \mathrm{MgO}, \mathrm{Ca}_{3} \mathrm{~N}_{2},$ and $\mathrm{Mg}_{3} \mathrm{~N}_{2} .$ Predict the formula for a compound of (a) magnesium and sulfur, (b) barium and bromine.

Nicole Smina

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Problem 48

The formulas of some hydrides of second-period representative elements are as follows: $\mathrm{BeH}_{2}, \mathrm{BH}_{3}$, $\mathrm{CH}_{4}, \mathrm{NH}_{3}, \mathrm{H}_{2} \mathrm{O}, \mathrm{HF}$. A famous test in criminology laboratories for the presence of arsenic (As) involves the formation of arsine, the hydride of arsenic. Predict the formula of arsine.

Nicole Smina

Numerade Educator

Problem 49

Clearly distinguish between the following terms and provide specific examples of each: groups (families) of elements and periods of elements.

Nicole Smina

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Problem 50

Write names and symbols for (a) the alkaline earth metals; (b) the Group $4 \mathrm{~A}$ elements; $(\mathrm{c})$ the Group $2 \mathrm{~B}$ elements.

Nicole Smina

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Problem 51

Write names and symbols for (a) the alkali metals; (b) the noble gases; (c) the Group $4 \mathrm{~A}$ elements.

Nicole Smina

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Problem 52

Clearly and concisely define the following terms and provide examples of each: (a) metals; (b) nonmetals; (c) halogens.

Nicole Smina

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Problem 53

Calculate the wavelengths, in meters, of radiation of the following frequencies: (a) $4.80 \times 10^{15} \mathrm{~s}^{-1}$ (b) $1.18 \times 10^{14} \mathrm{~s}^{-1}$ (c) $5.44 \times 10^{12} \mathrm{~s}^{-1}$.

Jennifer Hudspeth

Jennifer Hudspeth

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Problem 54

Calculate the frequency of radiation of each of the (a) 8973Å; following wavelengths: (b) $442 \mathrm{nm} ;$ (c) $4.92 \mathrm{~cm} ;$ (d) $4.55 \times 10^{-9} \mathrm{~cm} .$

Jennifer Hudspeth

Jennifer Hudspeth

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Problem 55

What is the energy of a photon of each of the radiations in Exercise $53 ?$ Express your answer in joules per photon. In which regions of the electromagnetic spectrum do these radiations fall?

Jennifer Hudspeth

Jennifer Hudspeth

Numerade Educator

Problem 56

Excited lithium ions emit radiation at a wavelength of $670.8 \mathrm{nm}$ in the visible range of the spectrum. (This characteristic color is often used as a qualitative analysis test for the presence of $\mathrm{Li}^{+} .$ ) Calculate (a) the frequency and (b) the energy of a photon of this radiation. (c) What color is this light?

Jennifer Hudspeth

Jennifer Hudspeth

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Problem 57

Calculate the energy, in joules per photon, of the red line, $6573 \AA$, in the discharge spectrum of atomic calcium.

Jennifer Hudspeth

Jennifer Hudspeth

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Problem 58

Ozone in the upper atmosphere absorbs ultraviolet radiation, which induces the following chemical reaction:
$$
\mathrm{O}_{3}(\mathrm{~g}) \rightarrow \mathrm{O}_{2}+\mathrm{O}
$$
What is the energy of a $3400-A$ photon that is absorbed? What is the energy of a mole of these photons?

Jennifer Hudspeth

Jennifer Hudspeth

Numerade Educator

Problem 59

During photosynthesis, chlorophyll- $\alpha$ absorbs light of wavelength $440 \mathrm{nm}$ and emits light of wavelength $670 \mathrm{nm}$. How much energy is available for photosynthesis from the absorption-emission of a mole of photons?

Jennifer Hudspeth

Jennifer Hudspeth

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Problem 60

Alpha Centauri is the star closest to our solar system. It is 4.3 light-years away. How many miles is this? A light year is the distance that light travels (in a vacuum) in one year. Assume that space is essentially a vacuum.

Jennifer Hudspeth

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Problem 61

What evidence supports the idea that electromagnetic radiation is (a) wave-like; (b) particle-like?

Ronald Prasad

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Problem 62

Describe the influence of frequency and intensity of electromagnetic radiation on the current in the photoelectric effect.

Jennifer Hudspeth

Jennifer Hudspeth

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Problem 63

Cesium is often used in "electric eyes" for selfopening doors in an application of the photoelectric effect. The amount of energy required to ionize (remove an electron from) a cesium atom is 3.89 electron volts $\left(1 \mathrm{eV}=1.60 \times 10^{-19} \mathrm{~J}\right) .$ Show by calculation whether a beam of yellow light with wavelength $5830 \AA$ A would ionize a cesium atom.

Jennifer Hudspeth

Jennifer Hudspeth

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Problem 64

Refer to Exercise $63 .$ What would be the wavelength, in nanometers, of light with just sufficient energy to ionize a cesium atom? What color would this light be?

Jennifer Hudspeth

Jennifer Hudspeth

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Problem 65

(a) Distinguish between an atomic emission spectrum and an atomic absorption spectrum. (b) Distinguish between a continuous spectrum and a line spectrum.

Ronald Prasad

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Problem 66

Prepare a sketch similar to Figure $4-18 \mathrm{~b}$ that shows a ground energy state and three excited energy states. Using vertical arrows, indicate the transitions that would correspond to the absorption spectrum for this system.

Crystal Wang

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Problem 67

Why is the Bohr model of the hydrogen atom referred to as the solar system model?

Nicole Smina

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Problem 68

If each atom in one mole of atoms emits a photon of wavelength $5.50 \times 10^{3} \AA$, how much energy is lost? Express the answer in $\mathrm{kJ} / \mathrm{mol}$. As a reference point, burning one mole $(16 \mathrm{~g})$ of $\mathrm{CH}_{4}$ produces $819 \mathrm{~kJ}$ of heat.

Jennifer Hudspeth

Jennifer Hudspeth

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Problem 69

What is the Balmer-Rydberg equation? Why is it called an empirical equation?

Ronald Prasad

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Problem 70

Hydrogen atoms absorb energy so that the electrons are excited to the energy level $n=7$. Electrons then undergo these transitions: (1) $n=7 \rightarrow n=1 ;$ (2) $n=7 \rightarrow n=2$; (3) $n=2 \rightarrow n=1$. Which of these transitions will produce the photon with (a) the smallest energy; (b) the highest frequency; (c) the shortest wavelength? (d) What is the frequency of a photon resulting from the transition $n=6 \rightarrow n=1 ?$

Crystal Wang

Numerade Educator

Problem 71

A Five energy levels of the He atom are given in joules per atom above an arbitrary reference energy:
(1) $6.000 \times 10^{-19}$
(2) $8.812 \times 10^{-19}$
(3) $9.381 \times 10^{-19}$
(4) $10.443 \times 10^{-19}$
(5) $10.934 \times 10^{-19}$.
Construct an energy level diagram for He, and find the energy of the photon (a) absorbed for the electron transition from level 1 to level 5 and (b) emitted for the electron transition from level 4 to level 1 .

Ronald Prasad

Numerade Educator

Problem 72

The following are prominent lines in the visible region of the emission spectra of the elements listed. The lines can be used to identify the elements. What color is the light responsible for each line?
(a) lithium, $4603 \AA$ A;
(b) neon, $540.0 \mathrm{nm} ;$
(c) calcium, $6573 \mathrm{~A}$;
(d) potassium, $\nu=3.90 \times 10^{14} \mathrm{~Hz}$

Jennifer Hudspeth

Jennifer Hudspeth

Numerade Educator

Problem 73

Hydrogen atoms have an absorption line at $1026 \AA$. What is the frequency of the photons absorbed, and what is the energy difference, in joules, between the ground state and this excited state of the atom?

Ronald Prasad

Numerade Educator

Problem 74

An argon laser emits blue light with a wavelength of $488.0 \mathrm{nm}$. How many photons are emitted by this laser in 2.00 seconds, operating at a power of 515 milliwatts? One watt (a unit of power) is equal to 1 joule/second.

Ronald Prasad

Numerade Educator

Problem 75

(a) What evidence supports the idea that electrons are particle-like? (b) What evidence supports the idea that electrons are wave-like?

Nicole Smina

Numerade Educator

Problem 76

(a) What is the de Broglie wavelength of a proton moving at a speed of $2.50 \times 10^{7} \mathrm{~m} / \mathrm{s} ?$ The proton mass is $1.67 \times 10^{-24} \mathrm{~g} .$ (b) What is the de Broglie wavelength of a stone with a mass of $30.0 \mathrm{~g}$ moving at $2.00 \times 10^{5} \mathrm{~m} / \mathrm{h}$ $(\approx 100 \mathrm{mph}) ?(\mathrm{c})$ How do the wavelengths in parts (a) and (b) compare with the typical radii of atoms?

Crystal Wang

Numerade Educator

Problem 77

What is the wavelength corresponding to a neutron of mass $1.67 \times 10^{-27} \mathrm{~kg}$ moving at $2360 \mathrm{~m} / \mathrm{s} ?$

Nicole Smina

Numerade Educator

Problem 78

What is the velocity of an $\alpha$ -particle (a helium nucleus) that has a de Broglie wavelength of $0.529 A$ ?

Nicole Smina

Numerade Educator

Problem 79

(a) What is a quantum number? What is an atomic orbital?
(b) How many quantum numbers are required to specify a single atomic orbital? What are they?

Nicole Smina

Numerade Educator

Problem 80

How are the possible values for the angular momentum quantum number for a given electron restricted by the value of $n$ ?

Nicole Smina

Numerade Educator

Problem 81

Without giving the ranges of possible values of the four quantum numbers, $n, \ell, m_{\ell},$ and $m_{s},$ describe briefly what information each one gives.

Nicole Smina

Numerade Educator

Problem 82

Draw an orbital that has the following quantum numbers: $n=3, \ell=1, m_{\ell}=-1,$ and $m_{s}=-\frac{1}{2}$.

Jennifer Hudspeth

Jennifer Hudspeth

Numerade Educator

Problem 83

What is the maximum number of electrons in an atom that can have the following quantum numbers? (a) $n=2 ;$ (b) $n=3$ and $\ell=1 ;$ (c) $n=3, \ell=1$, and $m_{\ell}=0$ (d) $n=3, \ell=1, m_{\ell}=-1,$ and $m_{s}=-\frac{1}{2} .$

Jennifer Hudspeth

Jennifer Hudspeth

Numerade Educator

Problem 84

What is the maximum number of electrons in an atom that can have the following quantum numbers? (a) $n=3$ and $\ell=1 ;$ (b) $n=3$ and $\ell=2$; (c) $n=3, \ell=0$ and $m_{\ell}=-1 ;$ (d) $n=3, \ell=1,$ and $m_{\ell}=-1 ;$ (e) $n=3$ $\ell=1, m_{\ell}=0,$ and $m_{s}=-\frac{1}{2}$

Jennifer Hudspeth

Jennifer Hudspeth

Numerade Educator

Problem 85

What are the values of $n$ and $\ell$ for the following subshells?
(a) $1 s ;$
(b) $3 s ;$
(c) $5 p ;$
(d) $3 d$;
(e) $4 f$.

Jennifer Hudspeth

Jennifer Hudspeth

Numerade Educator

Problem 86

(a) How many sublevels are in the third main energy level?
(b) Which, if any, of these sublevels contain a set of equivalent orbitals?
(c) Sketch, on the same relative scale, at least one orbital from each of these sublevels.

Jennifer Hudspeth

Jennifer Hudspeth

Numerade Educator

Problem 87

(a) How many sublevels are in the second main energy level?
(b) Which, if any, of these sublevels contain a set of equivalent orbitals? (c) Sketch, on the same relative scale, at least one orbital from each of these sublevels.

Jennifer Hudspeth

Jennifer Hudspeth

Numerade Educator

Problem 88

How many individual orbitals are there in the third shell? Write out $n, \ell$, and $m_{\ell}$ quantum numbers for each one, and label each set by the $s, p, d, f$ designations.

Jennifer Hudspeth

Jennifer Hudspeth

Numerade Educator

Problem 89

(a) Write the possible values of $\ell$ when $n=4$. (b) Write the allowed number of orbitals (1) with the quantum numbers $n=3, \ell=1 ;(2)$ with the quantum numbers $n=2, \ell=1 ;$ (3) with the quantum numbers $n=3$, $\ell=1, m_{l}=-1 ;(4)$ with the quantum number $n=1 .$

Jennifer Hudspeth

Jennifer Hudspeth

Numerade Educator

Problem 90

What are the possible values for $m_{\ell}$ for (a) the $p$ sublevel? (b) the $f$ sublevel? (c) all sublevels where $n=3$ ?

Jennifer Hudspeth

Jennifer Hudspeth

Numerade Educator

Problem 91

Write a complete set of quantum numbers $\left(n, \ell,\right.$ and $\left.m_{\ell}\right)$ for each of the following orbitals: (a) $5 f ;$ (b) $4 d$; and (c) $2 s$.

Abdel Osman

Numerade Educator

Problem 92

How many orbitals correspond to each of the following designations? (a) $3 p ;(b) 4 p ;(c) 4 p_{x} ;$ (d) $6 d ;$ (e) $5 d ;$ (f) $5 f$; (g) $n=5 ;$ (h) 7 s

Katherine Mccandless

Katherine Mccandless

Numerade Educator

Problem 93

The following incorrect sets of quantum numbers in the order $n, \ell, m_{\ell}, m_{s}$ are written for paired electrons or for one electron in an orbital. Correct them, assuming the $n$ values are correct.
(a) $1,0,0,+\frac{1}{2},+\frac{1}{2}$
(b) $2,2,1, \frac{1}{2} ;$
(c) $3,2,3, \pm \frac{1}{2}$
(d) $3,1,2,+\frac{1}{2}$;
(f) $3,-0,-1,-\frac{1}{2}$
(e) 2,1,-1,0

Jennifer Hudspeth

Jennifer Hudspeth

Numerade Educator

Problem 94

(a) How are a $1 s$ orbital and a $2 s$ orbital in an atom similar? How do they differ? (b) How are a $3 p_{x}$ orbital and a $2 p_{y}$ orbital in an atom similar? How do they differ?

Jennifer Hudspeth

Jennifer Hudspeth

Numerade Educator

Problem 95

Draw representations of ground state electron configurations using the orbital notation $(\uparrow \downarrow)$ for the (a) F; following elements. (b) $\mathrm{V} ;$ (c) $\mathrm{Br}$; (d) $\mathrm{Rh}$.

Jennifer Hudspeth

Jennifer Hudspeth

Numerade Educator

Problem 96

Draw representations of ground state electron configurations using the orbital notation $(\uparrow \downarrow)$ for the following elements.
(a) $\mathrm{P} ;$
(b) $\mathrm{Ni}$;
(c) Ga;
(d) Cd.

Jennifer Hudspeth

Jennifer Hudspeth

Numerade Educator

Problem 97

Determine the number of electrons in the outer occupied shell of each of the following elements, and indicate the principal quantum number of that shell.
(a) $\mathrm{Na}$;
(b) $\underline{\text { S; }}$
(c) Si;
(d) Sr;
(e) $\mathrm{Ba} ;$ (f) $\mathrm{Br}$.

Jennifer Hudspeth

Jennifer Hudspeth

Numerade Educator

Problem 98

Explain why each of the following ground state configurations is incorrect, and correct it.
(a) $\mathrm{Si}$
(b) $\mathrm{Ni}$
(c) $S$

Anand Jangid

Numerade Educator

Problem 99

Explain why each of the following ground state configurations is incorrect, and correct it.
(a) $\mathrm{Ca} 1 \mathrm{~s}$
(b) $\mathrm{V}[\mathrm{Ar}]$
(c) $\mathrm{F}$ 1s $\underline{\mathrm{N}}$

Jennifer Hudspeth

Jennifer Hudspeth

Numerade Educator

Problem 100

A neutral atom has two electrons with $n=1$, eight electrons with $n=2,$ eight electrons with $n=3,$ and two electrons with $n=4$. Assume this element is in its ground state configuration.
(a) What are the atomic number, symbol, and name of this element?
(b) In which period of the periodic table does this element appear?
(c) In which group of the periodic table does this element appear?
(d) What is the total number of $s$ electrons in this atom?
(e) What is the total number of $p$ electrons in this atom?
(f) What is the total number of $d$ electrons in this atom?

Jennifer Hudspeth

Jennifer Hudspeth

Numerade Educator

Problem 101

A neutral atom has two electrons with $n=1$, eight electrons with $n=2$, sixteen electrons with $n=3,$ and two electrons with $n=4$. Assume this element is in its ground state configuration.
(a) What are the atomic number, symbol, and name of this element?
(b) In which period of the periodic table does this element appear?
(c) In which group of the periodic table does this element appear?
(d) What is the total number of $s$ electrons in this atom?
(e) What is the total number of $p$ electrons in this atom?

Jennifer Hudspeth

Jennifer Hudspeth

Numerade Educator

Problem 102

With the help of Appendix $\mathrm{B}$, list the symbols for the first five elements, by atomic number, that have an unpaired electron in an $s$ orbital. Identify the group in which most of these are found in the periodic table.

Jennifer Hudspeth

Jennifer Hudspeth

Numerade Educator

Problem 103

List the elements having an atomic number of 20 or less that have one or more unpaired $p$ orbital electrons. Indicate the group to which each of these elements belongs in the periodic table.

Jennifer Hudspeth

Jennifer Hudspeth

Numerade Educator

Problem 104

Identify the element or elements possible, given only the number of electrons in the outermost shell and the principal quantum number of that shell. (a) 1 electron, first shell; (b) 3 electrons, second shell; (c) 3 electrons, third shell; (d) 2 electrons, seventh shell; (e) 4 electrons, third shell; (f) 8 electrons, fifth shell.

Jennifer Hudspeth

Jennifer Hudspeth

Numerade Educator

Problem 105

Give the ground state electron configurations for the elements of Exercise 95 using shorthand notation - that is, $[\mathrm{He}] 2 s^{2} 2 p^{6},$ and so on.

Jennifer Hudspeth

Jennifer Hudspeth

Numerade Educator

Problem 106

Give the ground state electron configurations for the elements of Exercise 96 using shorthand notation - that is, $[\mathrm{He}] 2 s^{2} 2 p^{6},$ and so on.

Jennifer Hudspeth

Jennifer Hudspeth

Numerade Educator

Problem 107

State the Pauli Exclusion Principle. Would any of the following ground state electron configurations violate this rule: (a) $1 s^{3} ;$ (b) $1 s^{2} 2 s^{2} 2 p_{x}^{2} 2 p_{y}^{3} ;$ (c) $1 s^{2} 2 s^{2} 2 p_{x}^{2}$; (d) $1 s^{2} 2 s^{2} 3 s^{2}$ ? Explain.

Nicole Smina

Numerade Educator

Problem 108

State Hund's Rule. Would any of the following ground state electron configurations violate this rule:
(a) $1 s^{2}$;
(b) $1 s^{2} 2 s^{2} 2 p_{x}^{2}$
(c) $1 s^{2} 2 s^{2} 2 p_{x}^{1} 2 p_{y}^{1}$
(d) $1 s^{2} 2 s^{1} 2 p_{x}^{1} 2 p_{z}^{1}$
(e) $1 s^{2} 2 s^{1} 2 p_{x}^{2} 2 p_{y}^{1} 2 p_{z}^{1} ?$
Explain.

Nicole Smina

Numerade Educator

Problem 109

A Classify each of the following atomic electron configurations as
(i) a ground state,
(ii) an excited state, or
(iii) a forbidden state:
(a) $1 s^{2} 2 p^{3}$;
(b) $[\mathrm{Kr}] 4 d^{10} 5 s^{3}$
(c) $1 s^{2} 2 s^{2} 2 p^{6} 3 s^{2} 3 p^{6} 3 d^{12} 4 s^{2}$
(d) $1 s^{2} 2 s^{2} 2 p^{6} 3 s^{2} 3 p^{6} 2 d^{1}$
(e) $1 s^{2} 2 s^{2} 2 p^{8} 3 s^{2} 3 p^{5}$.

Jennifer Hudspeth

Jennifer Hudspeth

Numerade Educator

Problem 110

Which of the elements with atomic numbers of 11 or less are paramagnetic when in the ground atomic state?

Jennifer Hudspeth

Jennifer Hudspeth

Numerade Educator

Problem 111

Semiconductor industries depend on such elements as Si, $\mathrm{Ga}, \mathrm{As}, \mathrm{Ge}, \mathrm{B}, \mathrm{Cd},$ and $\mathrm{S} .$ Write the predicted electron configuration of each element.

Jennifer Hudspeth

Jennifer Hudspeth

Numerade Educator

Problem 112

The manufacture of high-temperature ceramic superconductors depends on such elements as Cu, O, La, Y, Ba, Tl, and Bi. Write the predicted electron configuration of each element.

Jennifer Hudspeth

Jennifer Hudspeth

Numerade Educator

Problem 113

In nature, potassium and sodium are often found together. (a) Write the electron configurations for potassium and for sodium. (b) How are they similar? (c) How do they differ?

Jennifer Hudspeth

Jennifer Hudspeth

Numerade Educator

Problem 114

Which elements are represented by the following electron configurations?
(a) $1 s^{2} 2 s^{2} 2 p^{6} 3 s^{2} 3 p^{6} 3 d^{10} 4 s^{2} 4 p^{3}$
(b) $[\mathrm{Kr}] 4 d^{10} 4 f^{14} 5 s^{2} 5 p^{6} 5 d^{10} 6 s^{2} 6 p^{3}$
(c) $[\mathrm{Kr}] 4 d^{10} 4 f^{14} 5 s^{2} 5 p^{6} 5 d^{10} 5 f^{14} 6 s^{2} 6 p^{6} 7 s^{2}$
(d) $[\mathrm{Kr}] 4 d^{5} 5 s^{2}$
(e) $1 s^{2} 2 s^{2} 2 p^{6} 3 s^{2} 3 p^{6} 3 d^{2} 4 s^{2}$

Jennifer Hudspeth

Jennifer Hudspeth

Numerade Educator

Problem 115

Repeat Exercise 114 for
(a) $1 s^{2} 2 s^{2} 2 p^{6} 3 s^{2} 3 p^{6} 3 d^{10} 4 s^{1}$
(b) $[\mathrm{Kr}] 4 d^{10} 4 f^{14} 5 s^{2} 5 p^{6} 5 d^{10} 6 s^{2} 6 p^{4}$
(c) $1 s^{2} 2 s^{2} 2 p^{6} 3 s^{2} 3 p^{5}$
(d) $[\mathrm{Kr}] 4 d^{10} 4 f^{14} 5 s^{2} 5 p^{6} 5 d^{10} 6 s^{2} 6 p^{6} 7 s^{2}$

Jennifer Hudspeth

Jennifer Hudspeth

Numerade Educator

Problem 116

Find the total number of $s, p,$ and $d$ electrons in each of the following: (a) P; (b) $\mathrm{Kr} ;$ (c) $\mathrm{Ni} ;$ (d) $\mathrm{Zn} ;$ (e) $\mathrm{Ti}$.

Ronald Prasad

Numerade Educator

Problem 117

Write the electron configurations of the Group $2 \mathrm{~A}$ elements $\mathrm{Be}, \mathrm{Mg}$, and $\mathrm{Ca}$ (see inside front cover). What similarities do you observe?

Jennifer Hudspeth

Jennifer Hudspeth

Numerade Educator

Problem 118

Construct a table in which you list a possible set of values for the four quantum numbers for each electron in the following atoms in their ground states. (a) $\mathrm{Na} ;$ (b) $\mathrm{O}$; (c) Ca.

Ronald Prasad

Numerade Educator

Problem 119

Construct a table in which you list a possible set of values for the four quantum numbers for each electron in the (b) S; following atoms in their ground states. (a) $\mathrm{Mg}$; (c) $\mathrm{Sc}$.

Ronald Prasad

Numerade Educator

Problem 120

Draw general electron structures for the A group elements using the $\uparrow \downarrow$ notation, where $n$ is the principal quantum number for the highest occupied energy level.
and so on

Ronald Prasad

Numerade Educator

Problem 121

Repeat Exercise 120 using $n s^{x} n p^{y}$ notation.

Ronald Prasad

Numerade Educator

Problem 122

List $n, \ell,$ and $m_{\ell}$ quantum numbers for the highest energy electron (or one of the highest energy electrons if there are more than one) in the following atoms in their ground states. (a) $\mathrm{Si} ;(\mathrm{b}) \mathrm{Ac} ;(\mathrm{c}) \mathrm{Cl} ;(\mathrm{d}) \mathrm{Pr}$

Jennifer Hudspeth

Jennifer Hudspeth

Numerade Educator

Problem 123

List $n, \ell,$ and $m_{\ell}$ quantum numbers for the highest energy electron (or one of the highest energy electrons if there are more than one) in the following atoms in their ground states. (a) Se; (b) Zn; (c) $\mathrm{Mg} ;$ (d) $\mathrm{Pu}$.

Jennifer Hudspeth

Jennifer Hudspeth

Numerade Educator

Problem 124

Write the ground state electron configurations for elements $A-E$.

Ronald Prasad

Numerade Educator

Problem 125

Repeat Exercise 124 for elements F-J.

Ronald Prasad

Numerade Educator

Problem 126

How many unpaired electrons are in atoms of $\mathrm{Na}, \mathrm{Ne}, \mathrm{Al}$, Be, $\mathrm{Br}$, As, and Ti?

Jennifer Hudspeth

Jennifer Hudspeth

Numerade Educator

Problem 127

(a) Distinguish between the terms "diamagnetic" and "paramagnetic," and provide an example that illustrates the meaning of each. (b) How is paramagnetism measured experimentally?

Ronald Prasad

Numerade Educator

Problem 128

Which of the following ions or atoms possess paramagnetic properties?
(a) $\mathrm{Br}$;
(b) $\mathrm{Kr}$
(c) $\mathrm{Ne}^{+}$
(d) $\mathrm{Fe} ;(\mathrm{e}) \mathrm{Br}^{-}$.

Jennifer Hudspeth

Jennifer Hudspeth

Numerade Educator

Problem 129

Which of the following ions or atoms possess paramagnetic properties?
(a) $\mathrm{Cl}^{-} ;$ (b) $\mathrm{Ca}^{2+} ;$
(c) Ca;
(d) $\mathrm{Ar}^{-}$
(e) $\underline{\text { Si. }}$

Jennifer Hudspeth

Jennifer Hudspeth

Numerade Educator

Problem 130

The atomic mass of chlorine is reported to be $35.5,$ yet no atom of chlorine has the mass of 35.5 amu. Explain.

Nicole Smina

Numerade Educator

Problem 131

Chemists often use the terms "atomic weight" and "atomic mass" interchangeably. Explain why it would be more accurate if, in place of either of these terms, we used the phrase "average atomic mass."

Nicole Smina

Numerade Educator

Problem 132

The diameter of an atom is about 100,000 times larger than the diameter of the nucleus of the atom. Suppose an atom is enlarged until its nucleus is the size of a basketball, which has a diameter of 9.39 inches. What would be the diameter of this enlarged atom?

Jennifer Hudspeth

Jennifer Hudspeth

Numerade Educator

Problem 133

Using the electron configurations of the elements, given in Appendix B, and Hund's Rule, determine which elements have a pair of electrons in every occupied orbital (no singles). Are they about half of the elements, rather small in number, or rather large in number? To what groups of elements do they belong?

Jennifer Hudspeth

Jennifer Hudspeth

Numerade Educator

Problem 134

Draw a three-dimensional representation of each of the following orbitals: (a) $3 p_{x} ;$ (b) $2 s ;$ (c) $3 d_{x y}$; (d) $3 d_{z^{2}}$.

Ian Lee

Numerade Educator

Problem 135

We often show the shapes of orbitals as drawings. What are some of the limitations of these drawings?

Ronald Prasad

Numerade Educator

Problem 136

An atom in its ground state contains 18 electrons. How many of these electrons are in orbitals with $\ell=0$ values?

Jennifer Hudspeth

Jennifer Hudspeth

Numerade Educator

Problem 137

Suppose that scientists were to discover a new element, one that has the chemical properties of the noble gases, and positioned directly below radon on the periodic table. Assuming that the $g$ orbitals of the elements preceding it in the period had not yet begun to fill, what would be the atomic number and ground state electron configuration of this new element?

Jennifer Hudspeth

Jennifer Hudspeth

Numerade Educator

Problem 138

For a lithium atom, give (a) its ground state electron configuration; (b) the electron configuration for one of its lowest energy excited states; and (c) an electron configuration for a forbidden or impossible state.

Nicole Smina

Numerade Educator

Problem 139

Suppose we could excite all of the electrons in a sample of hydrogen atoms to the $n=6$ level. They would then emit light as they relaxed to lower energy states. Some atoms might undergo the transition $n=6$ to $n=1,$ and others might go from $n=6$ to $n=5,$ then from $n=5$ to $n=4,$ and so on. How many lines would we expect to observe in the resulting emission spectrum?

Ronald Prasad

Numerade Educator

Problem 140

Examine each of the following statements. What is incorrect about each statement? How can each statement be changed to make it a correct statement?
(a) A hydrogen atom has one energy level.
(b) A lithium atom has three electrons, two in the $1 s$ sublevel and one in the $2 p$ sublevel.
(c) The angular momentum quantum number, $\ell$, of an electron in a $p$ sublevel has a value of 2 .
(d) Three electrons in a $p$ sublevel will occupy separate orbitals, so one will be positive (+1) , one will be neutral
(0), and one will be negative (-1) .
(e) Two electrons in the same orbital must have the same spin.

Jennifer Hudspeth

Jennifer Hudspeth

Numerade Educator

Problem 141

Antimatter is composed of antiparticles in the same way that normal matter is composed of particles. For every subatomic particle there exists an antiparticle with the same mass but opposite charge. The antielectron (or positron) has a positive charge, and the antiproton has a negative charge. In 1995 the European Organization for Nuclear Research (commonly known as CERN) announced that it had successfully created nine antihydrogen atoms using these antiparticles. Describe the composition of an antihydrogen atom. What's in the nucleus and what's outside the nucleus?

Jennifer Hudspeth

Jennifer Hudspeth

Numerade Educator

Problem 142

Two isotopes of hydrogen occur naturally $\left({ }^{1} \mathrm{H},>99 \%,\right.$ and $\left.{ }^{2} \mathrm{H},<1 \%\right)$ and two of chlorine occur naturally ( ${ }^{35} \mathrm{Cl}$, $76 \%,$ and ${ }^{37} \mathrm{Cl}, 24 \%$ ). (a) How many different masses of HCl molecules can be formed from these isotopes? (b) What is the approximate mass of each of the molecules, expressed in atomic mass units? (Use atomic weights rounded to the nearest whole number.) (c) List these $\mathrm{HCl}$ molecules in order of decreasing relative abundance.

Jennifer Hudspeth

Jennifer Hudspeth

Numerade Educator

Problem 143

$\mathrm{CH}_{4}$ is methane. If ${ }^{1} \mathrm{H},{ }^{2} \mathrm{H},{ }^{12} \mathrm{C},$ and ${ }^{13} \mathrm{C}$ were the only isotopes present in a given sample of methane, show the different formulas and formula weights that might exist in that sample.

Jennifer Hudspeth

Jennifer Hudspeth

Numerade Educator

Problem 144

Sodium is easily identified in a solution by its strong emission at $\lambda=589 \mathrm{nm}$. According to Einstein's equation, $E=m c^{2}$ (where $m$ is mass), this amount of energy can be converted into mass. What is the mass equivalent of one photon emitted by an excited sodium atom? $\left(1 J=1 \mathrm{~kg} \cdot \mathrm{m}^{2} / \mathrm{s}^{2}\right)$

Jennifer Hudspeth

Jennifer Hudspeth

Numerade Educator

Problem 145

A student was asked to calculate the wavelength and frequency of light emitted for an electron in an excited state $\mathrm{H}$ atom making the following transitions:
(a) $n=6 \rightarrow n=2,$ and $(b) n=6 \rightarrow n=3 .$ She was asked to determine whether she would be able to visually detect either of these electron transitions. Are her responses below correct? If not, make the necessary corrections.
(a) $1 / \lambda=\left(1.097 \times 10^{7} / \mathrm{m}\right)\left(1 / 2^{2}-1 / 6^{2}\right)=$
$2.44 \times 10^{6} / \mathrm{m} ; \lambda=244 \mathrm{nm}$
$$
\text { (b) } 1 / \lambda=\left(1.907 \times 10^{7} / \mathrm{m}\right)\left(1 / 3^{2}-1 / 6^{2}\right)=
$$
$9.14 \times 10^{5} / \mathrm{m} ; \lambda=1090 \mathrm{nm}$
She concluded that she couldn't see either of the transitions because neither is in the visible region of the spectrum.

Ronald Prasad

Numerade Educator

Problem 146

When compounds of barium are heated in a flame, green light of wavelength $554 \mathrm{nm}$ is emitted. How much energy is lost when one mole of barium atoms each emit one photon of this wavelength?

Jennifer Hudspeth

Jennifer Hudspeth

Numerade Educator

Problem 147

A 60-watt incandescent light bulb consumes energy at the rate of $60 \mathrm{~J} \cdot \mathrm{s}^{-1}$. Much of the light is emitted in the infrared region, and less than $5 \%$ of the energy appears as visible light. Calculate the number of visible photons emitted per second. Make the simplifying assumptions that $5.0 \%$ of the light is visible and that all visible light has a wavelength of $550 \mathrm{nm}$ (yellow-green).

Ronald Prasad

Numerade Educator

Problem 148

Classical music radio station KMFA in Austin broadcasts at a frequency of $89.5 \mathrm{MHz}$. What is the wavelength of its signal in meters?

Jennifer Hudspeth

Jennifer Hudspeth

Numerade Educator

Problem 149

(a) How many electrons are in $25.0 \mathrm{~g}$ of copper?
(b) How many electrons are in one mole of nitrogen molecules?

Jennifer Hudspeth

Jennifer Hudspeth

Numerade Educator

Problem 150

(a) How many electrons are in one mole of nitrogen molecules? (b) How many electrons are in $30.0 \mathrm{~g}$ of water?

Jennifer Hudspeth

Jennifer Hudspeth

Numerade Educator

Problem 151

(a) Which of the four elements listed was first isolated in a laboratory in Mexico?
(b) Which was discovered first?
(c) Which of the four elements are (is) not essential in our diet?
(d) Which has only two known nonzero oxidation states?

Ronald Prasad

Numerade Educator

Problem 152

From these data, calculate the atomic mass of nickel. How does your answer compare to the value found on the periodic table? How do the values you found compare to those in Exercise $31 ?$

Ronald Prasad

Numerade Educator

Problem 153

How many neutrons are present in an atom of each stable isotope of chromium? How does the data you found compare to that in Exercise $38 ?$

Jennifer Hudspeth

Jennifer Hudspeth

Numerade Educator

Problem 154

How old was he when he entered college? How old was he when he died?

Jennifer Hudspeth

Jennifer Hudspeth

Numerade Educator

Problem 155

(a) Locate the value for microcentury expressed in minutes. (b) Locate the so-called "New Scientific Units" and give your favorite one.

Jennifer Hudspeth

Jennifer Hudspeth

Numerade Educator