Question 1

Which of the following best describes the bonding in metallic solids?

Accepted Answer

Atoms are held together by a 'sea' of collectively shared electrons.

Question 2

Which type of solid is most likely to be a good electrical conductor in its pure form?

Accepted Answer

Metallic solid

Question 3

A crystalline solid differs from an amorphous solid in which of the following ways?

Accepted Answer

Crystalline solids have a regular repeating pattern of atoms.

Question 4

Which of the following is a property of ionic solids?

Accepted Answer

High melting and boiling points due to strong electrostatic attractions.

Question 5

What is the coordination number of Na+ in the NaCl (rock salt) structure?

Accepted Answer

$$6$$

Question 6

Which statement about polymers is correct?

Accepted Answer

Polymers consist of long chains of atoms connected by covalent bonds.

Question 7

Which type of cubic lattice has atoms at the corners and at the center of each face?

Accepted Answer

Face-centered cubic

Question 8

A unit cell of NaCl contains how many formula units of NaCl?

Accepted Answer

$$4$$

Question 9

Which packing arrangement is identical to the face-centered cubic structure?

Accepted Answer

Cubic close-packed (ABCABC...)

Question 10

Which of the following statements about semiconductors is true?

Accepted Answer

Semiconductors have conductivity between that of conductors and insulators.

Question 11

Which process is used to synthesize gold nanoparticles in colloidal methods?

Accepted Answer

Reduction of gold ions by sodium citrate.

Question 12

What is the main difference between addition and condensation polymerization?

Accepted Answer

Condensation polymerization involves the removal of a small molecule such as water.

Question 13

Which of the following is a real-world application of semiconductors?

Accepted Answer

Electrical circuits and components that act as switches.

Question 14

Which of the following best explains why ionic solids are electrical insulators?

Accepted Answer

Their electrons are localized and not free to move.

Question 15

What is the effect of decreasing the size of semiconductor nanoparticles (quantum dots)?

Accepted Answer

The band gap increases and the color shifts to blue.

Question 16

Which of the following is true about thermoplastics?

Accepted Answer

They can be melted and reshaped multiple times.

Question 17

Which equation correctly represents the reduction of gold ions to form gold nanoparticles?

Accepted Answer

$$Au^{3+} + 3e$$^- \rightarrow Au$$

Question 18

Which of the following is a condensation polymer?

Accepted Answer

Nylon

Question 19

Which property of metals is explained by the electron-sea model?

Accepted Answer

Electrical conductivity

Question 20

Which of the following best describes nanomaterials?

Accepted Answer

Materials with dimensions of 1-100 nm that exhibit unique properties compared to bulk materials.

Chapter 12: Solids and Modern Materials – Classification, Structure, and Properties

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