$\text{Packing Efficiency} = \frac{\text{Volume of atoms in unit cell}}{\text{Total volume of unit cell}} \times 100\%$

Question 1

Which of the following best explains why solids retain their shape and volume?

Accepted Answer

The particles in a solid are packed closely together and only vibrate in place.

Question 2

Which type of solid can be analyzed using X-ray crystallography?

Accepted Answer

Crystalline solids

Question 3

How many atoms are present in a simple cubic unit cell?

Accepted Answer

$1$ atom

Question 4

A body-centered cubic (bcc) unit cell contains how many atoms?

Accepted Answer

$2$ atoms

Question 5

Which of the following unit cells has the highest packing efficiency?

Accepted Answer

Face-centered cubic

Question 6

Which equation correctly represents the packing efficiency of a unit cell?

Accepted Answer

$	ext{Packing Efficiency} = \frac{	ext{Volume of atoms in unit cell}}{	ext{Total volume of unit cell}} 	imes 100\%$

Question 7

Which of the following statements about molecular solids is correct?

Accepted Answer

They have relatively low melting points due to weak intermolecular forces.

Question 8

Which solid is most likely to have the highest melting point?

Accepted Answer

A network covalent solid like diamond

Question 9

Which of the following best describes the arrangement of atoms in a face-centered cubic (fcc) unit cell?

Accepted Answer

Atoms at each corner and at the center of each face

Question 10

Which of the following is a property of ionic solids?

Accepted Answer

They have high melting points and conduct electricity when molten.

Question 11

Which factor increases the lattice energy of an ionic solid?

Accepted Answer

Smaller ionic radius and higher charge

Question 12

Which of the following best describes the structure of graphite?

Accepted Answer

Carbon atoms are arranged in sheets held together by dispersion forces.

Question 13

Which of the following is a characteristic of polymers?

Accepted Answer

They are made by linking together many small molecules called monomers.

Question 14

A copper crystal has a face-centered cubic (fcc) unit cell with a radius of $128$ pm. What is the length of the edge of the unit cell?

Accepted Answer

$a = 2\sqrt{2}r$

Question 15

Which of the following solids is held together primarily by metallic bonds?

Accepted Answer

Copper

Question 16

Which of the following best describes the difference between crystalline and amorphous solids?

Accepted Answer

Crystalline solids have a regular repeating pattern; amorphous solids do not.

Question 17

Which of the following is NOT a type of atomic solid?

Accepted Answer

Molecular solid

Question 18

Which of the following is a property of network covalent solids?

Accepted Answer

They are held together by strong covalent bonds and have very high melting points.

Question 19

Which of the following best describes the electrical conductivity of ionic solids?

Accepted Answer

They conduct electricity when molten or dissolved in water.

Question 20

Which of the following is a real-world application of X-ray crystallography?

Accepted Answer

Determining the arrangement of atoms in crystalline solids

Crystalline and Amorphous Solids: Structure, Classification, and Properties

Study Guide - Practice Questions