Properties

Question 1

List three form properties.

Answer 1

Shape
Surface
Size

Question 2

List five mechanical properties.

Answer 2

Fracture
Toughness
Yield strength
Tensile strength
Elastic modulus

Question 3

List three chemical properties.

Answer 3

Reactivity
Toxicity
Corrosion

Question 4

List three thermal properties.

Answer 4

SHC
Thermal expansion
Conductivity

Question 5

List two electrical properties.

Answer 5

Conductivity
Resistance

Question 6

List three optical properties.

Answer 6

Refract
Reflect
Absorb

Question 7

List three environmental properties.

Answer 7

Sustainability
Recyclable
Biodegradable

Question 8

List three characteristics of metals.

Answer 8

High thermal conductivity
Ductile
Corrodes easily

Question 9

List three characteristics of polymers.

Answer 9

Ductile
Corrosion resistant
Non-reactive

Question 10

List three characteristics of ceramics.

Answer 10

Brittle
Corrosion resistant
Recyclable

Question 11

List three characteristics of hybrid / composites.

Answer 11

High yield strength
Low density
Corrosion resistant

Question 12

What is the difference between yield strength and tensile strength?

Answer 12

YS is the maximum stress before permanent deformation.

TS is the point of fracture.

Question 13

List three properties of metallic materials.

Answer 13

Conductors
Ductile
Opaque

Question 14

List four properties of covalent materials.

Answer 14

Soft
Brittle
Insulators
Low melting point

Question 15

List three properties of ionic materials.

Answer 15

Hard
Insulator
Brittle
High melting points

Question 16

Define ductility.

Answer 16

Ability of a material to deform under tensile load.

Question 17

Define malleability.

Answer 17

Ability of material to deform under compressive load.

Question 18

Name four material properties that are determined by the atomic structure.

Answer 18

Electric conductivity
Opacity
Thermal conductivity
YM

Question 19

Why are ceramics poor conductors of heat?

Answer 19

Ceramics have ionic and covalent bonds which has no free electrons.

Free valence electrons (such as in metallic bonds) are required for good conductivity of heat.

Question 20

Which class of materials is best for reactors and why?

Answer 20

Metals

High ductility and tensile strength.

Question 21

What is the difference between metals and metallic glass?

Answer 21

Metals have a crystalline structure.

Metallic glass has an amorphous structure.

Question 22

Difference between metals and polymers on a stress-strain graph?

Answer 22

Polymers have less toughness compared to metals.

Smaller area under the graph.

Question 23

Why are polymers poor conductors or heat and electricity?

Answer 23

Polymers have covalent bonds which has no free electrons.

Free valence electrons (such as in metallic bonds) are required for good conductivity of heat.

Question 24

Define brittle.

Answer 24

A material that does not undergo plastic deformation but instead fractures.

Question 25

What arrangements can a solid material exist in?

Answer 25

Crystalline, semi crystalline or amorphous.

Question 26

List three material properties to consider when designing a heat exchanger.

Answer 26

Yield strength Thermal conductivity Thermal expansion

Question 27

What class of materials has a low fracture toughness?

Answer 27

Ceramics

Question 28

What is the name for ordered atomic arrangements? Give one example.

Answer 28

Crystalline Quartz

Question 29

What is the name for unordered atomic arrangements? Give one example.

Answer 29

Amorphous Glass

Question 30

Describe a crystalline structure.

Answer 30

Short range and long range order in regular repeating units.

Question 31

Describe an amorphous structure.

Answer 31

No regular repeating structures.

Question 32

How many types of crystal structure arrangements are there?

Answer 32

14

Question 33

What are the three most common crystal structure arrangements?

Answer 33

BCC (body centred cubic) FCC (face centred cubic) HCP (hexagonal closest packed)

Question 34

Define thermal conductivity.

Answer 34

Ability of a material to conduct heat.

Question 35

Define yield strength.

Answer 35

The maximum stress a material can withstand before undergoing permanent deformation.

Question 36

Define tensile strength.

Answer 36

The stress at which a material fractures.

Question 37

What class of materials has the highest hardness?

Answer 37

Ceramics Hardness depends on atomic bonding Ceramics have strong ionic and covalent bond.

Question 38

What is the best class of materials for building a reactor operating at constant pressure and elevated temperatures?

Answer 38

Metals High tensile strength and ductility