UNIT1.
1.L
eadisame
ta
ll
icc
ry
st
alh
avi
nga_______s
tr
uct
ure
.
a)FCC
b)BCC
c
)HC P
d)TCP
Ans
wer:a
Exp
lan
a t
i
on:Cry
st
all
in
esol
id
sarec
l
ass
i
fi
edase
it
hermet
al
li
corn
on-
met
al
li
c
.Pb
,al
ongwi
t
hCu
,Ag
,Al
,an
dNi
,ha
s
afac
e-
cent
er
edcub
icst
ruc
tu
re.
2.Whi
chofthef
oll
owi
nghasaHCPcr
yst
als
tr
uct
ure
?
a)W
b)Mo
c)Cr
d)Zr
Answer
:d
Expl
anati
on:C r
yst
all
in
es o
li
dsa r
ecla
ssi
f
ieda sei
thermetal
li
corno
n -
meta
ll
ic
.W,Mo ,andC rar
eexampl
esofth
e
body
-ce
n t
ere
dc ub
icst
ruct
ureofcrys
tal
s
.Th eHC Pstruct
urei
sfoun
dinMg ,Zn,Ti,Cd
,Zr ,andot
hers
.
3.Amorphoussoli
dshave_______s tructu
re.
a)Regula
r
b)Line
ar
c)I
rreg
u l
ar
d)Dendri
tic
.
Answer
:c
Expl
anati
on:Ma ter
ial
sinwh i
chthemole
culeisthebasi
cstr
uct
ura
l s
ol
idandhasanir
regu
larst
ruc
tur
eisknownas
amorphoussoli
d.Cry
st
all
ineso
lid
s,ontheotherhan d
,usual
lyar
ea r
rang
edinaregu
larma nn
er.
4.At________i ronc h
angesit
sBCCs truc
turetoFCC.
o
a)308 C
o
b)568C
o
c)771C
o
d)906 C
.
Answer
:d
Expl
anati
on:S i
mil
artome ta
ll
iccr
yst
als
,af ewno n-
metal
li
ccry
st
alsal
soch
angefo
rmd uetote
mper
atur
ea n
d
pre
ssu
red i
ff
erenc
es
. T
hispr
o c
es
sister
meda sp o
lymorphi
sm.Ir
onchang
esfr
omB CCatroomt e
mper
at
u r
etoFCC
o
f
o r
ma t90 6C .
5.Atroomt emper
atur
e,ti
nisformedin
to_________
a)Graytin
b)Wh i
teti
n
c)Redtin
d)Yel
lowtin
.
Answer
:b
Expl
anati
on:S i
mil
artome ta
ll
iccr
yst
als
,af ewno n-
metal
li
ccry
st
alsal
soch
angefo
rmd uetote
mper
atur
ea n
d
,p
res
sur
edi
ff
er
enc
es.
Tinc
ry
st
all
iz
esi
nan o
n-met
al
li
cdi
amo
nds
tr
uct
ure(
gr
ayt
i
n)a
tlo
wte
mpe
rat
ure
s.Atr
oom
t
empe
rat
ure
,itf
or
msametal
l
icst
ruc
tu
re(
wh i
t
eti
n).
a
dver
ti
se
ment
6.Wh i
cho fthefol
l
owingisap r
ope
rtyofnon-
me ta
ll
iccr
yst
als
?
a)Highlyd uc
til
e
b)Lessbritt
le
c)Lowe lec
tri
calc
onduct
ivi
ty
d)FCCs truct
ure
.
Answer:c
Expl
ana t
ion:Non-met
a l
l
iccr
y s
tal
sarel
essduct
il
ea n
dh avel
owelec
tri
ca
lcon
duc
tiv
it
y.Ontheot
herha
n d,met
al
li
c
cry
stal
sa redif
fe
ri
ngsincet
heyaremo r
ed uc
ti
leandh av
eh i
ghel
ec
tr
icalc
ond
uct
ivi
t
y.
7.Wh i
cho fthefol
l
owingisnotana mor
phousma te
ri
al?
a)Glass
b)Plast
ics
c)Lead
d)Ru b
bers
.
Answer:c
Expl
ana t
ion:Ma te
ri
alsinwh i
c
hthemo l
ecul
eisthebasi
cstr
uct
ural
soli
dandhasanir
re
gul
arstr
uct
urearekno
wn
asamo rphoussol
id
.Mo stamorpho
usma te
ria
lsa r
epol
ymerssuc
ha spl
ast
i
csandrub
ber
s.T
h emos
tco
mmo n
amorphou smater
ial
isglas
s.
8.Thec ryst
alla
tti
c
eh asa_________a rrang
ement
.
a)On e-
d i
mensio
nal
b)Two-dimensi
onal
c)Three-
dimensi
onal
d)Four-dimensi
onal
.
Answer:c
Expl
ana t
ion:Latt
ic
eisdefi
nedasthere
gulargeomet
ric
alarr
ange
mentofpoi
nt
sincry
st
alsp
ace.S
pac
eo rcr
yst
al
l
a t
ti
ceisat hree
-di
mensi
onalnet
workofimagi
naryli
n e
sconne
ct
ingtheat
oms.
9.Thes ma l
l
estpor
ti
ono ft
helatt
i
ceisknowna s__________
a)Latti
ces t
ruct
ure
b)Latti
cep o
int
c)Bravaiscry
stal
d)Un i
tc e
ll
.
Answer:d
Expl
ana t
ion:Latt
ic
eisdefi
nedasthere
gulargeomet
ric
alarr
ange
mentofpoi
nt
sincry
st
alsp
ace.T
heunitce
lli
sth
e
small
estpo r
ti
onofthelatt
i
ce,whi
chwhenr e
peate
dina l
ldir
ec
ti
onsgiv
esri
s
etoalatt
i
cest
ruc
ture
.
10.Bravaislat
ti
ceco
nsis
tsof__________s pac
elat
tic
es
.
a)Eleven
b)Twelve
c)Thi
rteen
d)Fourteen
,.
Answer:d
Expl
ana t
i
o n
:Therearefourt
ee
nwa ysinwh i
chp o
int
scanb earra
n ge
dinas p
acesotha
teachhasi
dent
ica
l
sur
roundings
.Thesefo
urtee
nspacela
tt
icescons
ti
tut
etheB r
a va
isspac
elat
tic
es
.
11.Au ni
tcel
lthatcont
ainsla
tti
cepoi
ntsonlyatthecor
nersisknownas_________
a)Pri
mi t
iveuni
tcell
b)Sec
o ndar
yu ni
tcel
l
c)Layere
du ni
tcel
l
d)Derive
du ni
tcel
l
.
Answer:a
Expl
ana t
i
o n
:Ifau ni
tcellc
hosencon
tai
n slat
ti
cepoi
nt
so nl
ya tit
sc o
rne
rs,i
tisca
ll
edap r
imit
iv
eorsi
mp l
euni
tce
ll
.
I
tcontainsonl
yon elat
ti
cepoi
ntsinc
eeachp o
intatth
eeightcorn
ersissh
a r
edequal
l
ywithadja
ce
ntunitce
ll
s
.
12.Theaxialr
el
ations
hipofamo noc
li
niccrys
tals
yste
mi sgive
na s___________
a)a=b=c
b)a=b≠c
c)a≠b=c
d)a≠b≠c
.
Answer:d
Expl
ana t
i
o n
:Thecrysta
l s
yst
emi safor
ma tbywh i
chcrys
tal s
tr
uctur
esarecl
ass
if
i
ed.Eac
hc ry
st
alsy
st
emi sde
fi
ne
d
bytherel
a t
io
nshi
pb e
tweenedgele
ngt
hsa ,b,andc.Formo nocl
in
ic,or
tho
rhombi
c,andtr
ic
li
n i
csy
st
ems,theax
ia
l
rel
at
ionshi
pisgi
venb ya≠b≠c .
13.Theaxialr
el
ati
o n
shi
po farhombohedralcr
yst
alsys
te
mi sgi
ve
na s___________
a)a=b=c
b)a=b≠c
c)a≠b=c
d)a≠b≠c
.
Answer:a
Expl
ana t
i
o n
:Thecrysta
l s
yst
emi safor
ma tbywh i
chcrys
tal s
tr
uctur
esarecl
ass
if
i
ed.Eac
hc ry
st
alsy
st
emi sde
fi
ne
d
bytherel
a t
io
nshi
pb e
tweenedgele
ngt
hsa ,b,andc.Forcubicandr h
ombohed
rals
yst
ems,theaxi
alr
el
ati
onsh
ipi
s
gi
venbya=b=c .
14.Theinte
rra
cia
l angl
esofah ex
agon
al cry
sta
l s
yst
ema regive
nb y__________
a)α=β=ϒ=9 0 o
b)α=β=9 0
oϒ=1 2
0 o
c)α=β=ϒ≠9 0o
d)α≠β≠ϒ≠9 0 o
.
Answer:b
Expl
ana t
i
o n
:Thecrysta
l s
yst
emi sasys
temb ywh i
chcry
stal s
tr
uctur
esarecl
ass
if
i
ed.Eac
hc r
yst
alsy
st
emi sde
fi
ne
d
bytherel
a t
io
nshi
pb e
tweenedgele
ngt
hsa ,b,andca ndint
eraxi
ala n
gle
sα,β,a ndϒ.Forh e
xag
onals
yste
m,the
i
n t
er
axialangl
esaregiv
enb yα=β=9 0 oϒ=1 20o.
15.Theinte
rr
aci
al ang
le
so fatric
li
ni
ccrysta
lsyst
ema r
eg i
venby__________
a)α=β=ϒ=9 0 o
b)α=β=9 0
oϒ=1 2
0 o
, c)α=β=ϒ≠9 0
o
d)α≠β≠ϒ≠9 0o
.
Answer
:d
Expl
anati
on:Thecrys
talsy
stemisas y
ste
mb ywh i
chcrys
talst
ruc
turesar
eclas
si
fi
ed.Eac
hcryst
alsys
temisde
fi
ned
bytherel
at
ionshi
pbetwee
nedgele
ngthsa,b,andca ndint
er
a x
ialangl
esα,β,a ndϒ. F
orthetri
cl
i
nicsy
ste
m,the
i
n t
er
axial
an g
lesar
eg iv
enbyα≠β≠ϒ≠9 0o.
16.Whatistheato
mi crad
iusofaB CCcry
sta
l s
truct
ure
?
a)a/2
b)a/4
c)a√2/4
d)a√3/4
.
Answer
:d
Expl
anati
on:Atomicradi
usisdef
i
neda shal
fthedis
tanc
ebetwee
nth ece
nte
rsoftwon e
ig
hbor
ingato
ms .
Theato
mic
radi
usofas i
mp l
ecubeandHC Pisa/2r e
spe
ct
ivel
y,wher
easiti
sa √2/4anda √3/4forFCCa ndBCCresp
ec
ti
ve
ly
.
17.Whatisthecoo
rdinat
io
nn umberofasimpl
ec ub
icst
ruc
ture?
a)6
b)8
c)10
d)12
.
Answer
:a
Expl
anati
on:Coord
inati
onnumb e
risdefi
ne
da sthenumberofneare
stnei
ghbor
ingat
omsinc r
yst
als
.Thecoo
rdi
nat
i
on
numberfo
rt h
es i
mplecubi
cstr
uct
ureis6,where
asitis8and1 2forB C
Ca ndFCCrespe
ct
iv
ely
.
18.Whatistheatomicpac
ki
n gfa
ctorofBCCstr
u c
ture
?
a)0.5
4
b)0.6
8
c)0.
74
d)0.96
.
Answer
:b
Expl
anati
on:Thedensit
yofpacki
nginac r
yst
alisdete
rmi
nedu s
ingtheato
micpacki
ngfac
tor(APF)
.T h
eAPFo f
FCCa ndHC Pstru
cture
sis0.74
,and0 .5
4forsimpl
ec u
bi
cstruc
ture
,wh e
re
asitis0.
6 8fo
rB CCstr
uct
ure
.
1.Thete
nde
ncyofadef
or
medsol
i
dtorega
init
sac
tua
lpro
por
ti
onsi
nsta
ntl
yuponunl
oad
ingkno
wnas
______________
a)Perf
ec
tl
yelas
ti
c
b)Dela
yedel
ast
i
ci
ty
c)I
n e
la
sti
cef
fe
ct
d)Plas
ti
ci
ty
.
Answer
:a
Expl
anat
ion
:Ifth
erec
ove
ryoft
heso
li
disi
nst
anta
neo
usandc
omp l
et
e,i
tisk
nownasper
fe
ctl
yel
as
ti
c.De
lay
ed
el
ast
ic
it
yisdef
i
nedasth
este
adymodeo
fsol
idre
cup
er
ati
on
,whil
ethein
el
ast
i
ceff
ec
tiswhe
nthere
cup
era
ti
onof
1.L
eadisame
ta
ll
icc
ry
st
alh
avi
nga_______s
tr
uct
ure
.
a)FCC
b)BCC
c
)HC P
d)TCP
Ans
wer:a
Exp
lan
a t
i
on:Cry
st
all
in
esol
id
sarec
l
ass
i
fi
edase
it
hermet
al
li
corn
on-
met
al
li
c
.Pb
,al
ongwi
t
hCu
,Ag
,Al
,an
dNi
,ha
s
afac
e-
cent
er
edcub
icst
ruc
tu
re.
2.Whi
chofthef
oll
owi
nghasaHCPcr
yst
als
tr
uct
ure
?
a)W
b)Mo
c)Cr
d)Zr
Answer
:d
Expl
anati
on:C r
yst
all
in
es o
li
dsa r
ecla
ssi
f
ieda sei
thermetal
li
corno
n -
meta
ll
ic
.W,Mo ,andC rar
eexampl
esofth
e
body
-ce
n t
ere
dc ub
icst
ruct
ureofcrys
tal
s
.Th eHC Pstruct
urei
sfoun
dinMg ,Zn,Ti,Cd
,Zr ,andot
hers
.
3.Amorphoussoli
dshave_______s tructu
re.
a)Regula
r
b)Line
ar
c)I
rreg
u l
ar
d)Dendri
tic
.
Answer
:c
Expl
anati
on:Ma ter
ial
sinwh i
chthemole
culeisthebasi
cstr
uct
ura
l s
ol
idandhasanir
regu
larst
ruc
tur
eisknownas
amorphoussoli
d.Cry
st
all
ineso
lid
s,ontheotherhan d
,usual
lyar
ea r
rang
edinaregu
larma nn
er.
4.At________i ronc h
angesit
sBCCs truc
turetoFCC.
o
a)308 C
o
b)568C
o
c)771C
o
d)906 C
.
Answer
:d
Expl
anati
on:S i
mil
artome ta
ll
iccr
yst
als
,af ewno n-
metal
li
ccry
st
alsal
soch
angefo
rmd uetote
mper
atur
ea n
d
pre
ssu
red i
ff
erenc
es
. T
hispr
o c
es
sister
meda sp o
lymorphi
sm.Ir
onchang
esfr
omB CCatroomt e
mper
at
u r
etoFCC
o
f
o r
ma t90 6C .
5.Atroomt emper
atur
e,ti
nisformedin
to_________
a)Graytin
b)Wh i
teti
n
c)Redtin
d)Yel
lowtin
.
Answer
:b
Expl
anati
on:S i
mil
artome ta
ll
iccr
yst
als
,af ewno n-
metal
li
ccry
st
alsal
soch
angefo
rmd uetote
mper
atur
ea n
d
,p
res
sur
edi
ff
er
enc
es.
Tinc
ry
st
all
iz
esi
nan o
n-met
al
li
cdi
amo
nds
tr
uct
ure(
gr
ayt
i
n)a
tlo
wte
mpe
rat
ure
s.Atr
oom
t
empe
rat
ure
,itf
or
msametal
l
icst
ruc
tu
re(
wh i
t
eti
n).
a
dver
ti
se
ment
6.Wh i
cho fthefol
l
owingisap r
ope
rtyofnon-
me ta
ll
iccr
yst
als
?
a)Highlyd uc
til
e
b)Lessbritt
le
c)Lowe lec
tri
calc
onduct
ivi
ty
d)FCCs truct
ure
.
Answer:c
Expl
ana t
ion:Non-met
a l
l
iccr
y s
tal
sarel
essduct
il
ea n
dh avel
owelec
tri
ca
lcon
duc
tiv
it
y.Ontheot
herha
n d,met
al
li
c
cry
stal
sa redif
fe
ri
ngsincet
heyaremo r
ed uc
ti
leandh av
eh i
ghel
ec
tr
icalc
ond
uct
ivi
t
y.
7.Wh i
cho fthefol
l
owingisnotana mor
phousma te
ri
al?
a)Glass
b)Plast
ics
c)Lead
d)Ru b
bers
.
Answer:c
Expl
ana t
ion:Ma te
ri
alsinwh i
c
hthemo l
ecul
eisthebasi
cstr
uct
ural
soli
dandhasanir
re
gul
arstr
uct
urearekno
wn
asamo rphoussol
id
.Mo stamorpho
usma te
ria
lsa r
epol
ymerssuc
ha spl
ast
i
csandrub
ber
s.T
h emos
tco
mmo n
amorphou smater
ial
isglas
s.
8.Thec ryst
alla
tti
c
eh asa_________a rrang
ement
.
a)On e-
d i
mensio
nal
b)Two-dimensi
onal
c)Three-
dimensi
onal
d)Four-dimensi
onal
.
Answer:c
Expl
ana t
ion:Latt
ic
eisdefi
nedasthere
gulargeomet
ric
alarr
ange
mentofpoi
nt
sincry
st
alsp
ace.S
pac
eo rcr
yst
al
l
a t
ti
ceisat hree
-di
mensi
onalnet
workofimagi
naryli
n e
sconne
ct
ingtheat
oms.
9.Thes ma l
l
estpor
ti
ono ft
helatt
i
ceisknowna s__________
a)Latti
ces t
ruct
ure
b)Latti
cep o
int
c)Bravaiscry
stal
d)Un i
tc e
ll
.
Answer:d
Expl
ana t
ion:Latt
ic
eisdefi
nedasthere
gulargeomet
ric
alarr
ange
mentofpoi
nt
sincry
st
alsp
ace.T
heunitce
lli
sth
e
small
estpo r
ti
onofthelatt
i
ce,whi
chwhenr e
peate
dina l
ldir
ec
ti
onsgiv
esri
s
etoalatt
i
cest
ruc
ture
.
10.Bravaislat
ti
ceco
nsis
tsof__________s pac
elat
tic
es
.
a)Eleven
b)Twelve
c)Thi
rteen
d)Fourteen
,.
Answer:d
Expl
ana t
i
o n
:Therearefourt
ee
nwa ysinwh i
chp o
int
scanb earra
n ge
dinas p
acesotha
teachhasi
dent
ica
l
sur
roundings
.Thesefo
urtee
nspacela
tt
icescons
ti
tut
etheB r
a va
isspac
elat
tic
es
.
11.Au ni
tcel
lthatcont
ainsla
tti
cepoi
ntsonlyatthecor
nersisknownas_________
a)Pri
mi t
iveuni
tcell
b)Sec
o ndar
yu ni
tcel
l
c)Layere
du ni
tcel
l
d)Derive
du ni
tcel
l
.
Answer:a
Expl
ana t
i
o n
:Ifau ni
tcellc
hosencon
tai
n slat
ti
cepoi
nt
so nl
ya tit
sc o
rne
rs,i
tisca
ll
edap r
imit
iv
eorsi
mp l
euni
tce
ll
.
I
tcontainsonl
yon elat
ti
cepoi
ntsinc
eeachp o
intatth
eeightcorn
ersissh
a r
edequal
l
ywithadja
ce
ntunitce
ll
s
.
12.Theaxialr
el
ations
hipofamo noc
li
niccrys
tals
yste
mi sgive
na s___________
a)a=b=c
b)a=b≠c
c)a≠b=c
d)a≠b≠c
.
Answer:d
Expl
ana t
i
o n
:Thecrysta
l s
yst
emi safor
ma tbywh i
chcrys
tal s
tr
uctur
esarecl
ass
if
i
ed.Eac
hc ry
st
alsy
st
emi sde
fi
ne
d
bytherel
a t
io
nshi
pb e
tweenedgele
ngt
hsa ,b,andc.Formo nocl
in
ic,or
tho
rhombi
c,andtr
ic
li
n i
csy
st
ems,theax
ia
l
rel
at
ionshi
pisgi
venb ya≠b≠c .
13.Theaxialr
el
ati
o n
shi
po farhombohedralcr
yst
alsys
te
mi sgi
ve
na s___________
a)a=b=c
b)a=b≠c
c)a≠b=c
d)a≠b≠c
.
Answer:a
Expl
ana t
i
o n
:Thecrysta
l s
yst
emi safor
ma tbywh i
chcrys
tal s
tr
uctur
esarecl
ass
if
i
ed.Eac
hc ry
st
alsy
st
emi sde
fi
ne
d
bytherel
a t
io
nshi
pb e
tweenedgele
ngt
hsa ,b,andc.Forcubicandr h
ombohed
rals
yst
ems,theaxi
alr
el
ati
onsh
ipi
s
gi
venbya=b=c .
14.Theinte
rra
cia
l angl
esofah ex
agon
al cry
sta
l s
yst
ema regive
nb y__________
a)α=β=ϒ=9 0 o
b)α=β=9 0
oϒ=1 2
0 o
c)α=β=ϒ≠9 0o
d)α≠β≠ϒ≠9 0 o
.
Answer:b
Expl
ana t
i
o n
:Thecrysta
l s
yst
emi sasys
temb ywh i
chcry
stal s
tr
uctur
esarecl
ass
if
i
ed.Eac
hc r
yst
alsy
st
emi sde
fi
ne
d
bytherel
a t
io
nshi
pb e
tweenedgele
ngt
hsa ,b,andca ndint
eraxi
ala n
gle
sα,β,a ndϒ.Forh e
xag
onals
yste
m,the
i
n t
er
axialangl
esaregiv
enb yα=β=9 0 oϒ=1 20o.
15.Theinte
rr
aci
al ang
le
so fatric
li
ni
ccrysta
lsyst
ema r
eg i
venby__________
a)α=β=ϒ=9 0 o
b)α=β=9 0
oϒ=1 2
0 o
, c)α=β=ϒ≠9 0
o
d)α≠β≠ϒ≠9 0o
.
Answer
:d
Expl
anati
on:Thecrys
talsy
stemisas y
ste
mb ywh i
chcrys
talst
ruc
turesar
eclas
si
fi
ed.Eac
hcryst
alsys
temisde
fi
ned
bytherel
at
ionshi
pbetwee
nedgele
ngthsa,b,andca ndint
er
a x
ialangl
esα,β,a ndϒ. F
orthetri
cl
i
nicsy
ste
m,the
i
n t
er
axial
an g
lesar
eg iv
enbyα≠β≠ϒ≠9 0o.
16.Whatistheato
mi crad
iusofaB CCcry
sta
l s
truct
ure
?
a)a/2
b)a/4
c)a√2/4
d)a√3/4
.
Answer
:d
Expl
anati
on:Atomicradi
usisdef
i
neda shal
fthedis
tanc
ebetwee
nth ece
nte
rsoftwon e
ig
hbor
ingato
ms .
Theato
mic
radi
usofas i
mp l
ecubeandHC Pisa/2r e
spe
ct
ivel
y,wher
easiti
sa √2/4anda √3/4forFCCa ndBCCresp
ec
ti
ve
ly
.
17.Whatisthecoo
rdinat
io
nn umberofasimpl
ec ub
icst
ruc
ture?
a)6
b)8
c)10
d)12
.
Answer
:a
Expl
anati
on:Coord
inati
onnumb e
risdefi
ne
da sthenumberofneare
stnei
ghbor
ingat
omsinc r
yst
als
.Thecoo
rdi
nat
i
on
numberfo
rt h
es i
mplecubi
cstr
uct
ureis6,where
asitis8and1 2forB C
Ca ndFCCrespe
ct
iv
ely
.
18.Whatistheatomicpac
ki
n gfa
ctorofBCCstr
u c
ture
?
a)0.5
4
b)0.6
8
c)0.
74
d)0.96
.
Answer
:b
Expl
anati
on:Thedensit
yofpacki
nginac r
yst
alisdete
rmi
nedu s
ingtheato
micpacki
ngfac
tor(APF)
.T h
eAPFo f
FCCa ndHC Pstru
cture
sis0.74
,and0 .5
4forsimpl
ec u
bi
cstruc
ture
,wh e
re
asitis0.
6 8fo
rB CCstr
uct
ure
.
1.Thete
nde
ncyofadef
or
medsol
i
dtorega
init
sac
tua
lpro
por
ti
onsi
nsta
ntl
yuponunl
oad
ingkno
wnas
______________
a)Perf
ec
tl
yelas
ti
c
b)Dela
yedel
ast
i
ci
ty
c)I
n e
la
sti
cef
fe
ct
d)Plas
ti
ci
ty
.
Answer
:a
Expl
anat
ion
:Ifth
erec
ove
ryoft
heso
li
disi
nst
anta
neo
usandc
omp l
et
e,i
tisk
nownasper
fe
ctl
yel
as
ti
c.De
lay
ed
el
ast
ic
it
yisdef
i
nedasth
este
adymodeo
fsol
idre
cup
er
ati
on
,whil
ethein
el
ast
i
ceff
ec
tiswhe
nthere
cup
era
ti
onof
