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1- Thomson's Atom model :- The poNture chage
nfomy iibutedd ove hu ertiu 4pho and
he electron ave embeddel io hu sphe endt fhe
eleeteon at
3pouttue changu jut ake tada
fn a watemelonn or
or plums in ha pudding
" For his 9cason, Thomson's atom model i's also
Knauwn as plum- pudding moael .
Nof poshve chorge is egual to no ngatire
charge uch hat atom 'is eletrealiy natal.
Sught perhurbatiorn atoms Gause vYb ration
he eleetons abaut thuir eyuwl' bmium poho
Hadiation.
elehom emits elcto mgnute
Failut of Tho mson s mool :
olue to -
Popula in l9lI and lis cardeot Aaler
ine fn he case of
sewerel spectrl
cnd ohen afoms.
placn he Lange
Rubesford i Aypha Sattexing tapeiment
Obserwadions ;
d- patidu wee found to pa h7ogh
foil wihsut
2- Th
dfforent d- parhle în paing hroy
goa foit udogo aferent amunt of
dhe
sybetn
small numben of a- porhla (about
ve1 h'Bgooo)ooo) practscally nefachdl huin palhs
suforecl deflecton f neory J50".
H- The greph between m tolel numbe g d-porholes
v(os scatto edl through angle oand fhe scatteng
a was found to be as shousn in g
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The epou'menful obser ration lecd Ruhe forel
to the folawing conclukioni
l- Since most hu a- parhce pass ed mdeviatol
the atom has a lota cmpty Spoee in t
sfhce fast and heay d- por hle
chauld be
deflechd ewch hrough 180", h whole
f postive chorge prachcally he
enite mas he atom was con fincoto an
I is tall eol
Small cn rol foel.
exhemey
huclcus
Since 1 fnabaut &o00 d pohca is cfteckd
fhrcugh 780* h size of fhe nucls is a bout
{ sie of atom.
|O00o
Ruthrforcl s Atomn Moclel
On th basis e he Helulh sscatloung expeiment
Ruthenfordsg utec he follauwy pchre
4 the atom
1- Atom be negor cleol as a qbh gcbometer
and alino&t
/om bt whle g poukve choge
conceh batecl
the enitre o he atom s
mass
in asn all chhal coe called ncleus.
a- Th huucleus is surrouncl ecl by electons.
In ofhe wordi, the eleehona w sprcad
Ovet he Memaiving port ha atom
Peny empy ape in he aom.
DAQw backs Ruse ford 3 Alom moddel
J- whn the elctuon Cvalvc raund the nucls, hy
Conincusly acccluatel dowords h cenre
nueleus.
Acconding to horcntz,an aceleralol chorgel
por Hil shauled odiadu con tin euky.
clecho
fhec foke j in the atom, a
shallel con
nuelwing
emut eneryard hd
he acbs f ik path shauld" Cn olec
anel ultimatuly i shoutd fall into he
huclse.
Tlswevcc ) elechon evlue round he nuel
cwtthaut faling ato ¿ty herafn- Ruherfor
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fhecfiu ) in he aton, a HCUcluing cluchon
shatlel con Hn auty emut ener anl hence
path shauld
the stacus
and ultimafuy
Cn
it shoud fall inb he olecrcasf
huclesa.
Tlewea ; elechon evcluc round he nweleus
cwihout fallig oto ts the fore - Ruherforels
atom moclal cannet enplain e slabuty
Hu attom.
Rulherforcls afom moclul is true, he
electron can revolwc fn orbik et all possBl
addii and hence it should emit contn ews
enegy spectum: Hewewe he atoms-ke
hycragenpons tine pechum
Distance of ClosestApproach
Conrdv d por Hele mM m posses fohal
t a cus tanee
e , whn i
velouly
from 'the nucluu f an afom
atomc mumbn .
-) the kihetic
At the listanct f closest convertecl
cneg a- pasticd is
into petential energy
(2c)(2e)
ro
4T6o 4nu2
Impat PaRAmETER
The in fpaet panomete s lifinedaa the perpendiularn
distanc vec/o the t- poricle
from the cenhe f the nucles, when it is far
awcuy from hea lo m.
.....-0 Nactu
ze?ote2
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2
41To
n9 2
2
PHoTON
Apholor is packe f cnergg "Ik possesses rheg
Wheu h=6-62 X/o-3 Tis
BoHR ATomic MoDEL
Bohs adopf eel Rume forcl moolul afom 9 adet.
Some pos Fulat esS
() he electron in a stable orbrt dos'net Hadiat
enongy mokze2
ta angular
Ci) A sta bl o7bit is hat in which
mcles is cn
momenum t he elechron abs4t
:h=l 2,3, - -. n 0
(1i) The eletuon can absorb o7 TadaU eherg
onyi he eteehon jumps from
to Lawe,
hghen
orb
fala fom o hyher
Qv) The energy emutteol or abs0rbeol is a
phoon frequeng
E h2
BomR's THEORY OF Hy@Ro 6EN ATOM
angula momentum fo nh orbit z n
nh circulor onbit= fo.sz94)n?
(IA°= (o"m)
En ene g he electon in Hhe nth or
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(iri)
En ene g he elechon in he nts orbi}
En = -13-6'ey
’ Toal
ineicatinheehe elechon
bound.i's an "gve
inding EnegY
(0 Ena- to, Ener qy.evtlel when an elechror
Jumps pom nah orbit to n, ovbit
Cha>n)
eruttecl
= ave o. fno jaues n wnt
whee R- Rydberg's tonslont for yogn
(v) For Gke alomn/ Spe cis t atomc
Radusi-= Botr ocius
oTbit!
Energy En z(-13-6)2 ev
motion he cls is also connder , h
eplacued y
heu M eclvce cl mas o elechor unol ha
9:59 KB/S
moion the nuclw i's also cons der , hu
m is
Whou M e clwce cl mass e elechon nd hucley
m M
In fhis Cas e
En (-3-6èv) u
me
SPECTRAL SeRIES
(» Lyman Senies (Landing orbit n )
anetechon jumps from any gher eney
lewel naz 2, 3, 4, - to dBwee ehe
eseg spcal bine callea yman Semiey
which s elongi to he wlhrovlolt negion empuchen
n2 2, 3,4,- -.
(ii) Balmer Series!
do he tantilion
The spechat
n¡z 3, 4,s,-
dev'es
o n, : 2,ies
congondg
in thu 'visibl ancl i's calleel Belmn nes.
rii) Yaschen Series and n, =3,
we
get a apectal infrareed
9hiok j's calleol Pas then yenes.
"jen
ha 4, S, 6,. .
(iv) Brockett Series f na 5,6,7. and n, = 4
we
j t spec hral sens in the rfrarelreg
eh s caled Brackett Series.
nd ,
( ) PEund Series If naz 6, 78,. .
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(Iv) Brac kelt Sevies f n2 5,6,7 and n, = y
jet spec ral senes in thu
ohic s caled Brackett Series.
and n,:5
() Pfund Series : If na 6,78,.
we ta spechal senes fn he infra red *ego
which is calleel Pfund
series.
na 6, 7, 8,
Energy level
slationasu sfates ch atom e *GoMes enteol
to somu
porallel houzental linea,drawtaccoding
Suilahl
En E - 136 eV
n2 b2
Limiatiorn Bohr's Theory
.Uke
ingl clcelron atom tndmoreYad
elcchron
afom wilh wo or
wruley orbk
2- t dou net enplaan trtt Orbils arc also
sheutd be chosen whe
poss Yblu
3- Zn Hhe spechunm s kycoges , lerlatn spchal na
closeel Uines
bychgen peh um
4- oplain
toee notinct fo hr man
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