《材料科学与工程基础》英文习题及思考题及答?/p>
第二?/p>
习题和思考题
Questions and Problems
2.6
Allowed values for the quantum numbers ofelectrons are as follows:
The
relationships
between
n
and
the
shell
designationsare
noted
in
Table
2.1.
Relative tothe subshells,
l
?/p>
0 corresponds to an
s
subshell
l
?/p>
1 corresponds to a
p
subshell
l
?/p>
2 corresponds to a
d
subshell
l
?/p>
3 corresponds to an
f
subshell
For the
K
shell, the four quantum numbersfor each of the two electrons in the 1
s
state, inthe order of
nlmlms
, are 100(1/2 ) and 100(-1/2 ).Write the four quantum
numbers
for
allof
the
electrons
inthe
L
and
M
shells,
and
notewhich
correspond
to
the
s
,
p
, and
d
subshells.
2.7
Give the electron configurations
for the followingions: Fe
2+
, Fe
3+
, Cu
+
, Ba
2+
,
Br
-
, andS
2-
.
2.17
(a)
Briefly
cite
the
main
differences
betweenionic,
covalent,
and
metallic
bonding.
(b)
State the Pauli exclusion principle.
2.18
Offer
an
explanation
as
to
why
covalently
bonded
materials
are
generally
less
dense than ionically or metallically bonded ones.
2.19
Compute the percents ionic character of the interatomic bonds for the following
compounds: TiO
2
, ZnTe, CsCl, InSb, and MgCl
2
.
2.21
Using Table 2.2, determine the number of covalent bonds that are possible for
atoms of the following elements: germanium, phosphorus, selenium, and chlorine.
2.24
On
the
basis
of
the
hydrogen
bond,
explain
the
anomalous
behavior
of
water
when it freezes. That is, why is there volume expansion upon solidification?
3.1
What is the difference between atomic structure and crystal structure?
3.2
What is the difference between a crystal structure and a crystal system?
3.4
Show for the body-centered cubic crystal structure that the unit cell edge length
a
and the atomic radius
R
are related through
a =
4
R
/
?/p>
3.
3.6
Show that the atomic packing factor for BCC is 0.68. .
3.27*
Show
that
the
minimum
cation-to-anion
radius
ratio
for
a
coordination
number
of
6
is
0.414.
Hint:
Use
the
NaCl
crystal
structure
(Figure
3.5),
and
assume that anions and cations are just touching along cube edges and across face
diagonals.