EXAM 3 ch 12 Flashcards
Quartz, a form of SiO2, which contains an ordered array of neutral, covalently bonded nonmetal units, is an example of
a molecular solid.
an ionic solid.
a metallic solid.
an amorphous solid.
an alloy.
a molecular solid
Obsidian, a form of SiO2, which contains no long-range ordering of any kind and is made up of bonded nonmetal units, is an example of
a molecular solid.
an ionic solid.
a metallic solid.
an amorphous solid.
an alloy.
an amorphous solid
Copper has a face-centered cubic unit cell. Which element do you also expect to have a face-centered cubic unit cell?
Na
K
Ti
Mg
Ag
Ag
Arrange the following metals in order of expected increasing density. All have a face-centered cubic unit cell.
Ni, Pd, Pt
Pt < Pd < Ni
Pt < Ni < Pd
Pd < Pt < Ni
Pd < Ni < Pt
Ni < Pd < Pt
Ni < Pd < Pt
What type of crystal structure produces an aaaaaa layering pattern?
hexagonal
body-centered cubic
face-centered cubic
hexagonal or body-centered cubic
simple cubic
simple cubic
n the sodium chloride unit cell, the chloride ions form a cube in which each side is arranged like the following figure. The circles represent the positions of the chloride ions on one square face of the cube. All the other faces are the same. What is the name of this unit cell?
simple cubic
x-face cubic
chloride-centered cubic
body-centered cubic
face-centered cubic
face-centered cubic
Which of the following statement(s) about the simple cubic unit cell is(are) correct?
It results from the square packing of atoms in layers.
The atoms lie at the corners of a cube.
Each atom has 6 nearest neighbors.
The stacking pattern can be represented by aaaa.
All these statements are correct.
All these statements are correct
In the cesium chloride unit cell shown, the cesium ions sit on the corners of a cube. What is the name of this unit cell?
simple cubic
cubic-centered
chloride-centered cubic
body-centered cubic
face-centered cubic
body-centered cubic
Which of the following unit cells has the lowest packing efficiency?
simple cubic
face-centered cubic
body-centered cubic
both face-centered and body-centered cubic
Simple, face-centered, and body-centered cubic all have the same packing efficiency.
simple cubic
Which of the following unit cells has the highest packing efficiency?
simple cubic
face-centered cubic
body-centered cubic
both face-centered and body-centered cubic
Simple, face-centered, and body-centered cubic all have the same packing efficiency.
face-centered cubic
How many nearest neighbor atoms are there around each atom in a simple cubic unit cell?
4
10
6
12
8
6
How many nearest neighbor atoms are there around each atom in a face-centered cubic unit cell?
4
10
6
12
8
12
How many nearest neighbor atoms are there around each atom in a body-centered cubic unit cell?
4
10
6
12
8
8
An atom in a particular unit cell has 8 nearest neighbor atoms around it. Which unit cell(s) is(are) possible?
simple cubic
hexagonal
body-centered cubic
face-centered cubic or hexagonal
face-centered cubic
body-centered cubic
Polonium crystallizes in a simple cubic pattern. How many polonium atoms are in each unit cell?
1
4
2
5
3
1
