Fundamentals of Materials Science and Engineering: An Integrated Approach, 3e

GTBL042-02 GTBL042-Callister-v3 September 26, 2007 1:44

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Questions and Problems • 35

IMPORTANT TERMS AND CONCEPTS

Atomic mass unit (amu)

Atomic number

Atomic weight

Bohr atomic model

Bonding energy

Coulombic force

Covalent bond

Dipole (electric)

Electron configuration

Electron state

Electronegative

Electropositive

Ground state

Hydrogen bond

Ionic bond

Isotope

Metallic bond

Mole

Pauli exclusion principle

Periodic table

Polar molecule

Primary bonding

Quantum mechanics

Quantum number

Secondary bonding

Valence electron

van der Waals bond

Wave-mechanical model

REFERENCES

Most of the material in this chapter is covered

in college-level chemistry textbooks. Two are

listed here as references.

Brady, J. E., and F. Senese,Chemistry: Matter and Its

Changes, 4th edition, John Wiley & Sons, Inc.,

Hoboken, NJ, 2004.

Ebbing, D. D., S. D. Gammon, and R. O. Rags-

dale, Essentials of General Chemistry, 2nd

edition, Houghton Mifflin Company, Boston,

2006.

QUESTIONS AND PROBLEMS

Additional problems and questions for this chapter may be found on both Student and

Instructor Companion Sites atwww.wiley.com/college/callister.

Fundamental Concepts

Electrons in Atoms

2.1Silicon has three naturally occurring isotopes:

92.23% of^28 Si, with an atomic weight of

27.9769 amu, 4.68% of^29 Si, with an atomic

weight of 28.9765 amu, and 3.09% of^30 Si, with

an atomic weight of 29.9738 amu. On the basis

of these data, confirm that the average atomic

weight of Si is 28.0854 amu.

2.2 (a)How many grams are there in one amu of

a material?

(b)Mole, in the context of this book, is taken

in units of gram-mole. On this basis, how

many atoms are there in a pound-mole of

a substance?

2.3Allowed values for the quantum numbers of

electrons are as follows:

n= 1 , 2 , 3 ,...

l= 0 , 1 , 2 , 3 ,...,n− 1

ml= 0 ,± 1 ,± 2 ,± 3 ,...,±l

ms=±^12

The relationships betweennand the shell des-

ignations are noted in Table 2.1. Relative to

the subshells,

l=0 corresponds to anssubshell

l=1 corresponds to apsubshell

l=2 corresponds to adsubshell

l=3 corresponds to anfsubshell

For theKshell, the four quantum numbers

for each of the two electrons in the 1sstate, in

the order ofnlmlms, are 100(^12 ) and 100(−^12 ).

Note:In each chapter, most of the terms listed in the “Important Terms and Concepts”

section are defined in the Glossary, which follows Appendix E. The others are important

enough to warrant treatment in a full section of the text and can be referenced from the table

of contents or the index.