stabiliy o aom as well as spetuwm

tes
Ruchenad's madel of abom faited to explain atom. To explain the cenept
radiatons emitedd and absebed by n
Planek's quantun teoy
and the Spectun o an atom, Bohn applied
shabiity atomie madel.
rodiatlam to Ruthuad' ademic
Pestulates 9 Bokn'a Atom Hodel :
atom hau a cmal
4o the extet that an
Ruthen<od'A model e atom is acceptable
Nuleus wheu shole mas and poibire charge the
paihdy chaged coe called conLenhated.
atom as Suppsed to he coaneel cenhe p coe hota ha vo cey hai
tik hai ki jo otÓm h
(Riuteos d ka madel sir yhi tk vdi hota hai)
chatye
mometum gtte that electoni Can reyole dinly
Beka's quanti zation condiien lon angutas intgnal mlt ple
lewelein which its
its angula mamentun
in hose ener

jinha mementn h/An ka indegal mulhiple ho

(Electon sir nli abits me ghumt hai
L= mvr = nh

revodes an Aun dtu nucleu

with a definik fed engyin circulo pat
Tho
o
* An elecon yaindng A loing
ired vaddius knon s tate si thaut
stalionay lerel.
eletsen is alss knon a
stahonoy mei au ek tixed nadius ke sshit
ghunta haj eh
(Elechon nucleu Ke asund He )
me hina eneg l e ya gain
a pheton on radiation , when it jumps hom higho
fem o
An dechen emit eneay in the tom
tiqhe se laes enayy
ikalke Aai photon i radiation hi fam mein j vo
(E lechon eny jate hai)
dewel meun
Behha tqyency conditon
 Rodius Revearlian leckonu
to Bol'a quantzation conditien e angulan momentun ghich states that elechons
Aceding rwele suly in thoe engy Levs, in which it angudan mô men tum is

indegnal mutiple o hl 2n.

Le mvY nh

nh
21 mr
Consides an atom eleton ol massm and
a nucleu having atomic choge rusing ith veloity v areund
numbes 2.
Ten the
entipetal oe required by elehen ii prarided ay dy
athacien betsen nudes and elecken aconding to cauatien : elechotaic loe of

Kq.4 mv

Ke2e mv

kZe my

in
puting
K2e m n6
r
4a'mr
m n'
2 2
K2e

h'nlo
4nm Ze
re n'A Eo

2
r«n

radius e n obit Va n

n’
 Blechons
Revolution
tion fan anguls momedum stats thad elechea can
ncedng te Boh's qucutiuation condi
reveue in thoe cnegy dela, in which ik angulan
omvtum is an
angulas m

L: mvr n h
2

n h

lonsido on dechen aith ma mand chonge ee revsbing

nd choge with welecityv aend
arsund a

atami nunben z. Then the centipehal toe reauired by the

heteen nudeus and
eleton deckostat done t athadion
leken auodng to

my

O in ()
puting
my2
Ke (ze) + n h
dT m

K2ex m
nh
2 n K2e'

V
4nl, nh
2e
2¬o nh

n’
n

Ze' veleityenergyeletson
b it
in nth
2E n h
 n
nTa
3nTa
2p m Jt
n' 471
2
m2
e .
2n/n'h'Eo]y
2nhE.
X
2e mTI
Ze
pudthiny
in
nhlo 2 2Ze m JI
Ze'
and
: and
o Eo hn' that Knew
2nr
Speed
Dictano Time A
Election kReuelution Fos Peisd Time
 Kinelic Enou Elechon

2
2nhlo
m

2
m Z

kl-e) (2e)
r

- KZe n'h to
m TI Ze

-KZe m 2e
nh'

4nl, n'AEo
2

- m 2e

P.: -m Z
 Totat Enety Elbm
k£ + P.£:
Tstal EnegH
Let mze
&n'h-,'

then, TE. K+ (- 2k)

TE. -K
- l m2e 2
8 n'h

T-E. = - | m Ze
8 nth' ,
an ateic
Line Emissien specthum i sexies e lines o vanieLs wavelongtu emitted hy
vaplur wually xatd by elecki wtat pased thuauh it.
spehum o t enymitt ed
1Shen wlite light poaes thaeugh a gu ot vapous, thsn the
Jigkd shsowed with a gpectemeteei ghos some dak ines shich replae
Same

sion Speckum e the gu. Tkis type g spectum is

ines seen in the emissien
bigkt dines
ahaoap tion spechurn.
soech al sines emiHed duue to tho tanton e an electhen om any highen onbit
spectad teies
(n;: 2,3,4,5,...) + the Sivat abit n, ) fom a
Lyman cehies.
an elechon fom any higkon bit
* The spect al inea emited due to the tansition
(n; 3,4, 5, 6,.. ) to the second
hit stete (n,: 2) om a peiet
Spectal £esie hnsn s Balnes seies.
spechl ies eited due to the tamiton e an elethon m any highes
(n, 2 4,5, 6,--) to the tikd bit on eeCBndl eingy ctatt n 3) fom
Speehal series Knon a Pacchen sehies

LBPBP ’ lo Baby Pile Baby Please

L>s ymann, Balmsn, Raschen, Bracketl, Phund.

(3-6 3- 41 |-51 O-85. 054, 0.3 8 -, 0.

 Rydbesg fermule
radliated in the om o poston shen
atom, enengy is radiated the
Accsading ts Bohs' medel o okans
dekonin Audasqen atenm jumgs rem kighun enegJ hit to losey hgy oahi,

- 13-6 eV
6. 63 y1ox3x1o*
n; )
13-6e v
-

6-63x103x 1o

-038 ev nG

-0-54eV n25
Pfund Buited
-0-85ev
n1 States
Brac ket

-|-51ev n=3
Pasehen

intra-rec
Eneagy

-3-4leVT
Balmer
CVigible)

n
Graund
- 13-6 Shate
ev Lyman
* Radiua o irat oabit Muydsegen atom is 0-529 À.
Speod o electtan in ivt orbit o hydvegen isisSpeec ef lightc) (3x)0 ms
137
 de- Brgie' Grplanalon eo Bahn' Seord Poastdate e Suankzaton rngln
Momgntum
The

muliple tho de- Braglie awelngth the

elechon meiny in the obit.
i.e y 2 nlo s w n 1,2, 3, .... etc

mv

puting in 0
n

mv

nh

angula momeutum

liitakou Q Boh's Atemde Model

* This model cannot explain the spectha o camplex atoms

haing
elathon.
Behs'y mbdel ed atom cannst euplah fihe shutus the <peehal ines e Bames
sehies.
Beis' ato rae medel does not give auy
dishi buten o lehon \n an tom.
indiaten rgding tho

This nodel cannot aceunt fa ts yce natue eleto.

Tt doel net gi ve auy eeeGtnt i des abeut the velatie intcniies e spectel
Sines in the petum.
* TRis mê del cauld met asplain the Zeman (ect ie splktg spehal ine into
* Tais model coud not explain Ctak ie the cpliting Spechal as into a
no cpetal ines ndes te elechie ficld.
 o Qn cton ae
and
atom and
atom all
all tho positiv changes
Amost all o mas e tho
tho emall negien named nucleus e the ctom.
Cencendhaed Wy
atom.
cia the udeus is exckamely cmall as

asund te nuleus.
negatiey chay ed patdes knosn au eletons revolue
So most th space in tho nucleus is empty.
in the
No- rev oluing electens is eqyead to tho number d peite chnges
udeu whale is eleckically neuta.
Drucbaks Ruttelend' Hodel e Atem
tho atemn.
** ailed to explain the stabili'y
by anatom.
to euplain tue camplex spectum emited

Jnpat Parameter s tho pexpendjulaa distane beteen to tenhe e nucleus and

divectton o te veleity vect aloha patde shen the oe o inderation is mininm
betcen nudes and alpha pantde.
The angle between tho direchen e bppaoach a the od phe patce an d
the diveien e tte
Denoted
eadtened algha patile k alled scatoing ange.

The minimum distane ed a pant om the nueleus upto thich an energetie

N- patde tavelling divecty touada te ucdeus Cun mr just belai Conng to
distane lonest appreach.
rest and thon
Dengted bo.
rehaing
I kelpa esti
9 Degine atom.
The emaleat invisible poide e an elemet that (an exist is l<nb an tom. Ato nd
Congist a Amall dense nudeus protons and neuthony swwwended by revsl ving
ele hns in dlu bik. Eveuy atom is a ephee a radiud o the der
m. Ato m is
eleically neha and cantaiw equal amounk posi tive and
negahie chaga.
: Explain Rutheyads a potde scatening exporiment.
Kutlkerfovd and ais Aoe asoiates H. Geiges and e. ManLden consideyed "B as a
- partdey. A paalel beam -pat les enery 5-5 Mev oas alosed
thick gold oil.
2:lx lo m
Threngh a rotable deteton, consisthng e a zinu sulplide souan and a minoicope, ik
OA ond Hhat a-pattdes got stattehed. The scattered a- patiles produe lashes
on zinc Sulphde Tkese {leashes ight were Lounted at dillerent
ongles taom he direkion o ini dent keam.

Radioachne

'Zns cuted cUen

(a-particle da tct)
Lend cavity
(aimator
hiroope detcct
hotatahe
detectoh

0 Write obsonakena Rutheond' -pantiele scatening epeiment.

" Most the a- pontieles pas shaig ht thaaugh the gold foil. T+ meQns thy d not
colision wit qed atom.
Ony abt 014 % incident a- ptide scalter by me than o
moe
Abeut one a- pttide in evey 8000 « paticdes deylects by nthan 90.
0. rite concusion Ruthe od 'a a- paatile ecateaing experimtat.
Salteing
pesithe
e a patlea is due to Caudomb'a indesstien szhoten theu tue char and a
tho atom,
hage in
An atom ha a Lot spae
the ercire mass atom ls conined t6 an
Preckally m
efemey smal cental ou, nudea
Distanu the elechona hom uua is abeut io to lo time tho size e the
d-otices secte due to the ntenae elechic died necs a nudeu. nude
The moe (s the distane the velaity vecte
ine
an a pauide t0m the cetal
Leser is the
angl alteing
o Explain Ruthe<ed Madl eg atom.
The eutire me chage and mot e ta mau a tho atom is conetated in a
Smal vouma caled nudes 1oith elehom vevei nq around te nuleus jut s
planet revoluea around the sun.
Centhi petal oe required fos te revlutien elech on ahound nudeu is proided
by the electostaie atraien hotueen the elechen and the nuels,
The ci2e the nuleus it lom ohich is small as tompaed to te
ci2e the atom (3l n ,
The -e
change en eleton rlund the nudeus is eqyual to poitre chge
udeus co atom as a Shole is electically neuthad.
9. Write limitatons Ructaeford Model e atom.
It could not esplain the stability atom decay.
( agn e hucleus ke around ghum rhe h cirulas motion as acelesated mot"
aeeleated chaa > EM w ve bnage energs niklegi » en sgy spiral path >
nucles and e coi de atem deehoyed
Umable to explain line spehum.
( As elecdions reveling around the nucleus is wnder coutinusus aceeler ction t
cente theia angte anguwas velocity and teony 9oukd chnge continubuay
spectm.)
They oould emit a condinuous spetrum instead e ine
8. Deline Impat Paameteu Cb).
The pependia distane the iiial elaity veter e the a- patides on Hhe couko.l
ine ho nucdeus the atom is caled impat prametea C6).

velaut
b= Ze ot/
K.E mt

-pati de dependa on the impat po amatea b

colisien
Trajecty
i sma en 8c angle ccateing lage. { bit lge, then a-patide
goes underiated.
bagine Angle e ccateng
Angle ay hich a particlea qdt deuiated om it iginal path ahcund the
udeus is caled angle seatteng
potda

Sotiehig lin dtgpec)

9 Erplain and fnd Distane uost Aqpooch.
At a cetain distane ro om
Conveting into electh6stadic pteti ad enengyg and a- patde canngt so farthn dese
to ucdeus tiis distane (ro is called distanu g dosut approah.
Devot: TME projeun (Tptad lechoil Emea)
closest pwt.
+0
closegt put.

2 9.20

(+2e)
my
42e
ro
my 4rto

emistien
otom cetd vevove in cetain stable obits stheut he
" An elecsen in an proided by elect kte
The centri petd foe reaired tar thein rotat is
e radiant enegs
athrat beheen eletem and
nude.
o ohich aneuer
An elechn reveues arsed the nueleus ony in thore hbits ohere h is the Plan ck's conatat
moment um CL) is an indegal mutiple e
ire. L nh
2n

" An elehon might make a tansiton

anbther e lose enegy
Oue to thansi ton, a photon is emited kavihg energy equal to the energ dierene
beb:en the initad and inad States. Ths freaeny emited photen i gien by

o. Prove Behb' Erglanaton. 0 Prove De- Broglie4 erplahat" ctabiiy atem

Derivat"e L: mvr z nh
2 TL hn
As L z myre 2T
2r nh
2r n h mt
my

mvrznh 2ar ne

Lznh
2T
9. Duine eneqiea Electhon n the statoray nbit etecton in Boka's
6. Deive velocity
C. stakonoy obi.
KZe' z my
K2e
KZe my my'

As K£ lmy NoJ, Lz mvr: nh

2

ri nh 2)
2nm
ih (D
2
mýz K2e,2nmv
nA
r
2 n K Ze
AsTE k.£+ P-E nh
T¬.2 - K2e K2ex2
2 (0-53¢) n ()
TE
K |TI |PI
2
. Deine ine Peried g electen in stehi 8nay
bit. 6bi.
deive radi Bohi'a Statonany
fe f.. T2 2rr
V
K 2e my'
ht
4a m Ke
my, kze
(aaKe) n
Nou, l mur: nh
2T

2nmr nmket
( in O T n
2

KZe. n

x n'

n'h
4n'K2e

4nm Ke

0 53 A n'
2
9 beine nd deince hequeny elechon in Bohh's stationay onbit.
Frequny lechen in Boha' stationay abit is Hhe number vevetiona
nucle,
Completed pe seond by the electen in a setinay sbit aneund tho
Ke'
n
nhr

9- Dride Jinni tations Boh Model.

"Applicable ony o the hychogen ake atom, hoviag Z=|. Tais
" Dees not explain te fine sthuctue e speutrad Jines in H- ctom.
" Does ngt rbit.
eyplain abet the shapea
begine Rydbeg's conatant.
Eest E -,e. h he

-13-6eV
n n,
13-6ev

136ev

6 13-bev |2376 A

Enesay level :
e,: -13-eVa ’ Grund ctate
U : ’lymann
E,2-34ev ’ Balme
-5lev 8ev rP ’ Paschen LJavlength
seies
0. 06ev
Exited ctatks
,:-08Sev red
P

from hiahes lewel to ower level > enesa is lost

* To hee the eect on, enegy reaui red
is 136ev and peteatial required is 13-6\1.
* Igization energ is the eneay ct shich electons
Toni 2ohion pttential iu ho qets ee
poten id dieno at which eleckh on gets ee
-13-6 cv N=
n 2
 atoma e awnged
hickneas e qold cil is egMal te tho ato mic dianeter so taat
one by on in a vertical aligumet
Goil i4 is uaed toz o it bigge atomic sie so than tin sheet is made eas4
*
ond co2 i4 is maleab le.

23r? nde cirunone has integnal no waelength

Speed elechon in firat bit bydhogen is Speed o ght 3x10
|37
131
an
Line emission spectum us senie o ines o vaious 90weleng tha emita
ato mic qas o vap buun wsually ereited by electic cwhent pasted troyh H.

* whon lite light passes tereugh a qas o vap ou, then the ipechuin
thansmited iaht obserwed oith a Spechemeter chons some dank inea whi ch
replae some sight ines seen in the emission spechum e the qas. This
ype peuhum is knesn as ahsoption spechum.
* The Spectal unea enitHed due t te
ansiton an electton from any bign
erbit (n, z 2,3,4,5,..-) to the dirst os bit (n1)hom a spech ad
series
Kngn as ymenn seies.
* Tonisoti on enegg an atom is de<ined au tta enesa required to remene an eletson em
its gound state eningu level to its ee Atae. Tonaation eey ko a hydosen atem i:
136ev Torisahion Eneay : -13-beV eV
n n'

Trgfechoy e a pasides in the Coulgm eld a tuget hudeus

* The total enesy the elecon is nagetine. This impiea the fat thak the electhon is baund
t9 the ndeus. TIn it woa pesiive, an electron sl not oe a clesed obit aheuynd
he nucdeus andH ould Jeave the atom.