Chapter 03 Physical and Mechanical Properties of Dental Materials

Chapter 03  Physical and Mechanical Properties of Dental Materials

Complete Chapter Questions And Answers
 

Sample Questions

MULTIPLE CHOICE

1. Which type of bond occurs when two atoms share electrons in their outer shell, creating full shells for both?
a.
Ionic bond
b.
Covalent bond
c.
Metallic bond
d.
Hydrogen bond

ANS: B
Covalent bonds occur when two atoms share electrons in their outer shell, creating full shells for both. Covalent bonds are very strong. Diamond is a good example of a strong covalent bond; it is hard and has a high melting point.

REF: p. 20 TOP: Physical Structure (Primary Bonds)

2. Which of the following is an example of a secondary rather than primary bond?
a.
Ionic bond
b.
Metallic bond
c.
Covalent bond
d.
Hydrogen bond

ANS: D
A hydrogen bond is an example of a secondary bond. Secondary bonds are much weaker than primary bonds. Unlike with primary bonds, no transfer or sharing of electrons occurs. This weakness often leads to deformation or fracture.

REF: p. 20 TOP: Physical Structure (Secondary Bonds)

3. Which of the following forms of matter has/have both shape and volume?
1. Solid
2. Liquid
3. Gas
a.
1, 2, 3
b.
1, 2
c.
2, 3
d.
1

ANS: D
Solids have the strongest attraction between atoms and molecules and have both shape and volume, a liquid has volume but no shape, and a gas has neither definite shape nor volume.

REF: p. 21 TOP: Physical Structure (The Three States of Matter)

4. If the molecules of a solid are arranged in a random form with no regular pattern, the solid is called:
a.
thixotropic.
b.
amorphous.
c.
malleable.
d.
ductile.

ANS: B
If the molecules of a solid are arranged in a random form with no regular pattern, the solid is called amorphous. The most stable solids have a regular crystalline structure with molecules in a regularly spaced pattern.

REF: p. 21 TOP: Physical Structure (Solids)