Module 3

Question 1

materials that contain more than one element

Answer 1

alloys

Question 2

types of alloys

Answer 2

SIH
SUBSTITUTIONAL, INTERSTITIAL, HETEROGENOUS ALLOYS

Question 3

element takes place of a metal atom

Answer 3

substitutional alloys

Question 4

element that fills a space in the lattice of metal atoms

Answer 4

interstitial alloys

Question 5

components not dispersed uniformly

Answer 5

heterogeneous alloys

Question 6

compounds not mixtures
distinct properties, definite composition, ordered rather than randomly distributed , more brittle than substitutional alloys

Answer 6

intermetallic compounds

Question 7

a group of cations suspended in a sea of electrons

Answer 7

metallic bonding

Question 8

the electron sea model would lead to increased attraction for every

Answer 8

electron added

Question 9

Rules of MO theory

Answer 9

1. atomic orbitals combine to make MOs to extend over the entire molecule
2. MO can contain 0,1,2 electrons
3. number of MOs equal the number of atomic orbitals
4. adding electrons to a bonding MO strengthens bonding, while adding them to antibonding MOs weakens bonding

Question 10

the number of atoms in a chain increases, the energy gap disappears resulting in

Answer 10

continuous band of energy

Question 11

held together by electrostatic attractions

Answer 11

ionic solids

Question 12

have very high melting and boiling points

Answer 12

ionic solids

Question 13

the charge is centered on the anions they are called

Answer 13

electronic insulators

Question 14

three common structures

Answer 14

CsCl structure
NaCl structure
Zinc blende

Question 15

consist of atoms or molecules held together by weaker forces

Answer 15

molecular solids

Question 16

ability to stack matters for some physical properties, like boiling point

Answer 16

shape

Question 17

example of molecular solids

Answer 17

graphite

Question 18

atoms are covalently bonded over large network distances with regular patterns of atoms

Answer 18

covalent-network solids

Question 19

example of covalent network solids

Answer 19

diamond

Question 20

have a gap between the occupied and not occupied band

Answer 20

semiconductors

Question 21

tend to have an average of four valence electrons

Answer 21

iorganic semiconductors

Question 22

have more electrons, so the negative charge travel in conductance band

Answer 22

n-type semiconductors

Question 23

have fewer electrons, so the hole travels in the valence band

Answer 23

p-type semiconductors

Question 24

are molecules of high molecular weight made by joining smaller molecules

Answer 24

polymers

Question 25

polymers are molecules of high molecular weight made by joining smaller molecules

Answer 25

monomers

Question 26

polymeric solids that can be formed into various shapes

Answer 26

plastics

Question 27

TYPES OF PLASTICS

Answer 27

Thermoplastics, thermosetting plastics, and elastomers

Question 28

a type of plastic that can be melted and reshaped

Answer 28

thermoplastics

Question 29

type of plastics that can be shaped through an irreversible chemical reaction

Answer 29

thermosetting plastics

Question 30

are rubbery, they stretch and return to shape

Answer 30

elastomers

Question 31

TYPES OF POLYMERS

Answer 31

AC Addition polymers Condensation polymers

Question 32

formed when a bond breaks and the electrons in that bond make two new bonds

Answer 32

addition polymers

Question 33

are formed when a small molecule is removed between two large molecules

Answer 33

condensation polymers

Question 34

two molecules are joined to make a larger molecule

Answer 34

condensation polymerization

Question 35

formed by two different monomers

Answer 35

copolymers

Question 36

can lead to crystallinity in the solid that makes the polymer denser, harder, less, and more resistant to heat

Answer 36

short range order

Question 37

in vulcanization chains are cross-linked by short chains of

Answer 37

sulfur atoms

Question 38

are semiconductors 1-10 nanometers in size

Answer 38

quantum dots

Question 39

allotropes of carbon

Answer 39

diamond, graphite, graphene, and buckyballs

Question 40

the only allotropes of carbon known were

Answer 40

diamond and graphite

Question 41

a new form of carbon that exist is discovered

Answer 41

discrete C60 molecules

Question 42

another name of buckyballs

Answer 42

buckminsterfullerene

Question 43

a single layer with the structure of graphite

Answer 43

graphene