In this essay, I will talk about something about the material of Military body armor,
Nomex is the mean material of the body armor.
In order to bulletproof demand, the material should
have high elasti
1.
Solution:
The formula is
QV
N v =Nexp
kT
Because of the data is the vacancies of unit volume Ag, so for V=1m3
V N A 9.5 g/cm 3 1 106 cm 3 6.02210 23
N= Ag
=
A Ag
107.9 g /mol
28
5.3 10
Transform
1.
Show that the minimum cation-to-anion radius ratio for a coordination number of
6 is 0.414. [Hint: use the NaCl crystal structure, and assume that anions and
cations are just touching along cube ed
The accompanying figure shows a unit cell for a hypothetical metal.
(a) To which crystal system does this unit cell belong?
(b) What would this crystal structure be called?
(c) Calculate the density o
1. (a) Using the ionic radii data in your textbook, calculate the coulombic force of
attraction between Na+ and Cl- in NaCl. You may want to check the structure of
NaCl to figure out the separation di
1.
Please describe in your own understanding what the crystal structure is. You are
expected to describe in both Chinese and English. Your description should be
from two directions as I discussed in c
Metallic Crystal Structures
1.
For the HCP crystal structure, show that the ideal c/a ratio is 1.633.
A
A
B
C
B
C
Solution:
In the HCP crystal structure, I choose A for the center atom. There are 12 a
1. Calculate the number of atoms contained in a cylinder 1 m in
diameter by 1 m deep of (a) magnesium and (b) lead.
Solution
(a) After check the table on book, I know the density of magnesium is 1.74g
1. Chemical analysis in materials science laboratories is frequently
done by means of the scanning electron microscope. In this
instrument, an electron beam generates characteristic x-rays that
can be
Crystallographic directions
1. For tetragonal crystals, cite the indices of directions that are equivalent to each of
the following directions:
(a) [101]; (b) [110]; (c) [010].
Solution:
1 ] , [ 0 1