2) For a face-centered cube, show the calculation to determine the number of atoms per cell and the total number of atoms in 6 unit cells. Page 541

General Chemistry - Standalone book (MindTap Course List)
11th Edition
ISBN:9781305580343
Author:Steven D. Gammon, Ebbing, Darrell Ebbing, Steven D., Darrell; Gammon, Darrell Ebbing; Steven D. Gammon, Darrell D.; Gammon, Ebbing; Steven D. Gammon; Darrell
Publisher:Steven D. Gammon, Ebbing, Darrell Ebbing, Steven D., Darrell; Gammon, Darrell Ebbing; Steven D. Gammon, Darrell D.; Gammon, Ebbing; Steven D. Gammon; Darrell
Chapter11: States Of Matter; Liquids And Solids
Section: Chapter Questions
Problem 11.113QP
icon
Related questions
Question

Please show step-by-step solution.

2) For a face-centered cube, show the calculation to determine the number of atoms per cell
and the total number of atoms in 6 unit cells. Page 541
Transcribed Image Text:2) For a face-centered cube, show the calculation to determine the number of atoms per cell and the total number of atoms in 6 unit cells. Page 541
12.3 Unit Cells and Basic Structures
541
RELATIONSHIPS USED:
V = 1³ (Volume of a cube)
4r
(Edge length of body-centered cubic unit cell)
V3
1 =
%3D
SOLVE
SOLUTION
Solve the equation for the volume of a cube for I and
substitute in the given value for V to find I.
V = 13
1 = Vv = V4.32 × 10-23 cm
3.5088 x 10-8 cm
%3D
Solve the equation for the edge length of a body-centered
cubic unit cell for r and substitute in the value of 1 (from the
4r
1 =
V3
previous step) to find r.
V31
V3 (3.5088 × 10 8 cm)
= 1.5193 x 10-8 cm
4
4
Convert r from cm to m and then to pm.
0.01 m
1 pm
1.5193 X 10-8 cm x
152 pm
%3D
1 cm
W Z1-0
CHECK The units of the answer (pm) are correct. The magnitude is reasonable because atomic radii range roughly from 50
to 200 pm.
FOR PRACTICE 12.3 An atom has radius of 138 pm and crystallizes in the body-centered cubic unit cell. What is the
volume of the unit cell in cm³?
The face-centered cubic unit cell (Figure 12.7▼) is a cube
Face-centered cubic
with one atom at each corner and one atom (of the same kind)
in the center of each cube face. Note that in the face-centered
unit cell (like the body-centered unit cell), the atoms do not
touch along each edge of the cube. Instead, the atoms touch
along the face diagonal. The edge length in terms of the atomic
radius is therefore I = 2V2r, as shown here.
62 = 12 + 1? = 21²
b = 4r
(4r)2 = 212
(4r)2
%3D
%3D
12
4r
%3D
V2
In the face-centered cubic lattice, the atoms touch
along a face diagonal. The edge length is 2V2r.
= 2V2r
Face-Centered Cubic Unit Cell
Coordination number = 12
Atoms/unit = x 8) + (G x 6) = 4
atom
atom
at 8 cornerS
at 6 faces
A FIGURE 12.7 Face-Centered Cubic Crystal Structure
The different colors used on the atoms in this figure are for
clarity only. All atoms within the structure are identical.
Transcribed Image Text:12.3 Unit Cells and Basic Structures 541 RELATIONSHIPS USED: V = 1³ (Volume of a cube) 4r (Edge length of body-centered cubic unit cell) V3 1 = %3D SOLVE SOLUTION Solve the equation for the volume of a cube for I and substitute in the given value for V to find I. V = 13 1 = Vv = V4.32 × 10-23 cm 3.5088 x 10-8 cm %3D Solve the equation for the edge length of a body-centered cubic unit cell for r and substitute in the value of 1 (from the 4r 1 = V3 previous step) to find r. V31 V3 (3.5088 × 10 8 cm) = 1.5193 x 10-8 cm 4 4 Convert r from cm to m and then to pm. 0.01 m 1 pm 1.5193 X 10-8 cm x 152 pm %3D 1 cm W Z1-0 CHECK The units of the answer (pm) are correct. The magnitude is reasonable because atomic radii range roughly from 50 to 200 pm. FOR PRACTICE 12.3 An atom has radius of 138 pm and crystallizes in the body-centered cubic unit cell. What is the volume of the unit cell in cm³? The face-centered cubic unit cell (Figure 12.7▼) is a cube Face-centered cubic with one atom at each corner and one atom (of the same kind) in the center of each cube face. Note that in the face-centered unit cell (like the body-centered unit cell), the atoms do not touch along each edge of the cube. Instead, the atoms touch along the face diagonal. The edge length in terms of the atomic radius is therefore I = 2V2r, as shown here. 62 = 12 + 1? = 21² b = 4r (4r)2 = 212 (4r)2 %3D %3D 12 4r %3D V2 In the face-centered cubic lattice, the atoms touch along a face diagonal. The edge length is 2V2r. = 2V2r Face-Centered Cubic Unit Cell Coordination number = 12 Atoms/unit = x 8) + (G x 6) = 4 atom atom at 8 cornerS at 6 faces A FIGURE 12.7 Face-Centered Cubic Crystal Structure The different colors used on the atoms in this figure are for clarity only. All atoms within the structure are identical.
Expert Solution
trending now

Trending now

This is a popular solution!

steps

Step by step

Solved in 2 steps

Blurred answer
Knowledge Booster
Crystal Lattices and Unit Cells
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, chemistry and related others by exploring similar questions and additional content below.
Similar questions
Recommended textbooks for you
General Chemistry - Standalone book (MindTap Cour…
General Chemistry - Standalone book (MindTap Cour…
Chemistry
ISBN:
9781305580343
Author:
Steven D. Gammon, Ebbing, Darrell Ebbing, Steven D., Darrell; Gammon, Darrell Ebbing; Steven D. Gammon, Darrell D.; Gammon, Ebbing; Steven D. Gammon; Darrell
Publisher:
Cengage Learning
Chemistry
Chemistry
Chemistry
ISBN:
9781305957404
Author:
Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste
Publisher:
Cengage Learning
Chemistry
Chemistry
Chemistry
ISBN:
9781133611097
Author:
Steven S. Zumdahl
Publisher:
Cengage Learning
Chemistry: An Atoms First Approach
Chemistry: An Atoms First Approach
Chemistry
ISBN:
9781305079243
Author:
Steven S. Zumdahl, Susan A. Zumdahl
Publisher:
Cengage Learning
Physical Chemistry
Physical Chemistry
Chemistry
ISBN:
9781133958437
Author:
Ball, David W. (david Warren), BAER, Tomas
Publisher:
Wadsworth Cengage Learning,
Chemistry: The Molecular Science
Chemistry: The Molecular Science
Chemistry
ISBN:
9781285199047
Author:
John W. Moore, Conrad L. Stanitski
Publisher:
Cengage Learning