Más contenido relacionado Más de Fikri Pandoez (20) 1. Fisika Atom 197
Bab
8
Fisika Atom
Hasil yang harus Anda capai:
menganalisis berbagai besaran fisis pada gejala kuantum dan batas-batas
berlakunya relativitas Einstein dalam paradigma Fisika Modern.
Setelah mempelajari bab ini, Anda harus mampu:
membuat ulasan tentang perkembangan teori atom
A. Evolusi Model
Atom
B. Atom Berelektron
Banyak
41@1CD9@5B18=54571BD5D171D?=D?==5BE@1;12181
41C1B@5IECEC5=E1J1DI171414911=99D5D1@91D?=2E;1@1BD9;5
D5B;539 ;1B51 =1C98 141 @1BD9;5@1BD9;5 CE21D?=9; *18E;18 41
DE:E1 @1B1 9=EG1 =5=@51:1B9 1D?= +DE; =5:1G12 @5BD1I11
D5BC52ED 41 81BEC =5:1G12 D5B5298 418EE @5BD1I11@5BD1I11
25B9;ED @1;18 41 D18E D5D17 C5B1D ?@D9; I17 21I1; 497E1;1
411= 4E91 D55;?=E9;1C9 C5;1B17 99 @1;18 41 D18E 2181
1@1 I17 497E1;1 C521719 B17;1 @5C1G1D E1719; 571
=5=@51:1B9 C5E; 25E; 1D?= @1B1 9=EG1 41@1D =5=?4969;1C9 ECEB
ECEB C589771 =5=99;9 C961D I17 4981B1@;1
'141 212 99 41 1;1 =5=@51:1B9 5F?EC9 =?45 1D?= 41 1D?=
25B55;DB? 21I1; $1D5B9 99 =5BE@1;1 41C1B @575D18E1 EDE;
251:1B 41 =571@9;1C9;1 D5;??79 D5D17 69C9;1 =1D5B91
Sumber: Chemistry: Matter and Its Changes, 2003
Atom terdiri atas proton dan neutron yang terletak pada inti
serta elektron yang mengorbit pada kulit.
2. Tes Kompetensi Awal
#,),3;44,47,3(1(802659,70902(:642,81(2(53(/96(396(3),802;:+(3(4);2;3(:0/(5
)52ED;1 ;?=@?5 @5IECE C52E18 1D?= 41
:51C;1;54E4E;1D91@;?=@?5D5BC52ED411=
1D?=
3. )52ED;141:51C;1=?45=?451D?=I17@5B18
141=E1941B91G1C1=@19=?45I17D5B21BE
A. Evolusi Model Atom
)5:1; J1=1 4EE =1EC91 CE418 D5BD1B9; EDE; =575D18E9 2181
41C1B @5IECE C5EBE8 =1D5B91 41 J1D I17 141 49 11= 99 #141C1
25B@9;9BI1 C171D C545B811 =5B5;1 =571=29 11?79 C52E18 BE=18
I17 492E1D 41B9 21DE 41 ;1IE ;5=E491 21DE D5BC52ED 49CECE ?58
@1BD9;5@1BD9;521DEI175298;53941C5D5BECI1;89BI1=5B5;1
C1=@19 @141 ;5C9=@E1 218G1 2181 C5=E1 =1D5B91 41 J1D I17 141
49 11= 9DE 49CECE ?58 CE1DE 2181 41C1B
1. Model Atom Demokritus
45 D5D17 ;525B1411 2181 41C1B 99 ;19 @5BD1=1 49;5=E;1;1
?58,;*077;9189BD18E
)$5=E491,46280:;9
M
)$=575=217;1@541@1D,;*077;94571=5=25B91=1,'%'+
EDE;218141C1B99%1=199491=2941B92181C1/E19I1725B1BD9
D941; 41@1D 492179 179 !149 ,46280:;9 =5I1D1;1 218G1 C5=E1
=1D5B91 41 J1D I17 141 49 11= 99 49CECE ?58 21791 D5B;539 I17
D941; 41@1D 492179 179 I19DE 1D?=
'141 =1C1 D5BC52ED 21I1; @1B1 69CE6 I17 =575=E;1;1
@541@1DI1 =57519 1D?= B7E=5D1C9 I17 =5B5;1 7E1;1 2E;1
4941C1B;1@14181@5B3?211=519;125B41C1B;1?79;1-11E@E
@55=E1=5B5;199C521D1CD5?B9D5D1@98199D518=5:149D?771;
@5D97 EDE; @5;5=2171 D5?B9 69C9;1 1D?= 41 69C9;1 9D9 )59B97
4571 @5B;5=2171 J1=1 21I1; 69C9;1G1 41 ;9=91G1 I17
D5BD1B9; EDE; =5=@51:1B9 D5?B9 1D?= 99 D5BEC =5=2E1D 5F?EC9 =?45
1D?= C589771 4941@1D;1 =?45 1D?= C5@5BD9 C5;1B17 99
2. Model Atom Dalton
6/5 (3:65 M 14118 C5?B17 9=EG1 77B9C I17 ;19
@5BD1=1 =5I1D1;1 D5?B9 D5D17 1D?= 25B41C1B;1 81C9 5;C@5B9=5
I17 491;E;1 69,7/ !86;9: C5?B17 ;9=91G1 41B9 'B139C I17
=5I1D1;1 218G1 C5I1G1 49CECE ?58 ECEBECEB 4571
@5B214971 D5D1@ 1C9 5;C@5B9=5 !86;9: 99 49C52ED E;E=
'5B214971 *5D1@ '141 !86;9: =51;E;1 5;C@5B9=5 4571
=5B51;C9;1 ECEB 894B?75 41 ECEB ?;C975 1 =55=E;1 C5I1G1
19B 4571 @5B214971 D5D1@ I19DE 71B 41 5298 :51C
@5B81D9;1 D125 25B9;ED
198 Mudah dan Aktif Belajar Fisika untuk Kelas XII
)52ED;11=11=1;E9DD5=@1D55;DB?=57?B29D
411=1D?=4125B1@1:E=18=1;C9=E=55;DB?
I1741@1D25B141@141D91@;E9DD5BC52ED
?21 41 @5B81D9;1 D125 @5B9?49; ECEBECEB
$5EBED4121719=11;18E;EB1:1B9:1B91D?=
411=1C1DE@5B9?45412C1DE7??71
Tokoh
John Dalton
(1766–1844)
John Dalton adalah seorang
ilmuwan Inggris. Dia orang pertama
yang mengemukakan tentang teori
atom berdasarkan hasil eksperimen
yang dilakukan Joseph Proust. Dalton
menyatakan bahwa atom adalah
bagian terkecil dari benda yang tidak
dapat dibagi-bagi lagi.
Sumber: www.allbiographies.com
4. Fisika Atom 199
)51981C95;C@5B9=5'B?ECD5;C@5B9=519I1749:149;113E1
?58 1D? 411= =5=2E1D D5?B9 1D?=I1 14118 5;C@5B9=5 I17
491;E;1 ?58 5:605, (6090,8 41 !8,09:3,? '141 4E1 ?B17
;9=91G19DE=51;E;15;C@5B9=54571=5=11C;1=5B;EB9?;C941
I17 498E2E7;1 4571 E41B1 49 G1418 D5BDEDE@ 1C9 5;C@5B9=5
=5E:E;;1 =1CC1 C525E= B51;C9 41 C5CE418 B51;C9 14118 C1=1
'5BI1D11 99 49;51 C521719 E;E= #1F?9C95B
E1 81C9 5;C@5B9=5 99 =5=2E1D (3:65 =5=@5B31I19 D5D17
;525B1411 1D?= !9;1 CE1DE ECEB D5B49B9 41B9 2181 41C1B I17 D941;
;?D9E D941; =E7;9 141 @5B214971 D5D1@ ECEBECEB @5=25DE;
C5I1G1 41 ;5;5;11 =1CC1 58 ;1B51 9DE @141
1D?
=57ECE;1 D5?B9 1D?= C521719 25B9;ED
1 D?= =5BE@1;1 21791 D5B;539 CE1DE J1D I17 D941; 41@1D 492179
2179 179
2 )5D91@ ECEB =5=99;9 C961D E9; I17 C5CE19 4571 C961D 1D?=
@5IECEI1
3 E1 1D?= 1D1E 5298 I17 25B1C1 41B9 ECEBECEB 25B191 41@1D
25B712E7 =5=25DE; =?5;E
4 '141 CE1DE @5BC5I1G11 EDE; =5=25DE; =?5;E :E=18 =1CC1
C525E= 41 C5CE418 @5BC5I1G11 14118 C1=1
5 '141 CE1DE @5BC5I1G11 ECEBECEB @5=25DE;I1 C51E 25B141
411= @5B214971 D5D1@ 41 C545B811
3. Model Atom Thomson
'141 1;89B 1214 . . $/64(9 3( +0965 25B81C9 =55=E;1
65?=51 5=9C9 D5B=1 411= @5B3?211I1 EDE; =539@D1;1 2?1
1=@E 5?=51 99 =54?B?7 @1B1 69C9;1G1 =559D9 D5D17 D12E7
C91B ;1D?45 *12E7 C91B ;1D?45 D5B49B9 1D1C C52E18 D12E7 81=@1 71C
49411=D12E749@?=@1;5E1BC1=@19D5;1171CC5;9D1B
==7
C1DE55;DB?45571D96;1D?4541C1DE55;DB?41@?C9D961?455D9;1
55;DB?45498E2E7;14571CE=25BD57171D9779;,M
;,1;1
495=9C9;1 CE1DE @1BD9;5 I17 25B75B1; =5E:E 1?45 1B9 81C9
@559D91 49;5D18E9 218G1 @1BD9;5 I17 495=9C9;1 ;1D?45 99
25B=E1D1 571D96
'141C5?B1769C9;1G1 77B9C25B1=169,7/6/5$/64965
=51;E;1 ;5=219 5;C@5B9=5 D5D17 D12E7 C91B ;1D?45 D5D1@9
4571 2525B1@1 =?4969;1C9 +DE; 5298 :51CI1 41 29C1 =5981D
(4)(8 25B9;ED
Tokoh
Sir J.J. Thomson
(1856–1940)
Thomson adalah seorang ahli Fisika
yang lahir di Checham Hill, Greater
Manchester, Inggris. Dia belajar di
Cambridge dan meraih gelar
profesor pada 1884. Dia meraih
hadiah Nobel Fisika tahun 1906.
Eksperimennya yang terkenal
tentang tabung sinar katode. Dari
eksperimennya, dia menemukan
nilai nisbah e/m.
Sumber: www.allbiographies.com
(99(0+86.,5
?(5.08,(2902(5
.8(4
7. Gambar 8.1
Percobaan Thomson
(4)(8 =5E:E;;1 @141 21791 D5718 D12E7 C91B ;1D?45
4925B9 =541 9CDB9; 41 =541 =175D I17 1B18I1 C197 D571; EBEC
*'++ !$ I19DE =541 9CDB9; 25B1B18 ;5 21G18 @141 71=21B 41
=541=175D25B1B18;5411=;5BD1C@14171=21B*181@1D181@1
5;C@5B9=5 I17 491;E;1 ?58 $/64965 14118 C521719 25B9;ED
5D9;1
41
@1BD9;5 C91B ;1D?45 25B75B1; EBEC
8. 5D9;1 =541 9CDB9; 491;D96;1 C91B ;1D?45 25B75B1; ;5 1D1C 1
99 49C5212;1 71I1 55;DB?CD1D9C 1D1B1 @1BD9;5 25B=E1D1 571D96
41 @51D ;EDE2 @?C9D96
571 D5D1@ =5:171 25C1B =541 =175D 491;D96;1 )5CE19
4571 ;19418 D171 ;11 1B18 71I1 #?B5DJ 14118 ;5 21G18
571 =571DEB 25C1BI1 C91B ;1D?45 D5BC52ED 1;1 25B75B1;
EBEC ;5=219
1B9 5;C@5B9=5 D5BC52ED $/64965 =541@1D;1 @5B89DE71
=1D5=1D9C C521719 25B9;ED
51:E1 @1BD9;5 411= D12E7 C91B ;1D?45 4941@1D;1 41B9
@5BE2181 55B79 @?D5C91 9CDB9; =5:149 55B79 ;95D9; @1BD9;5
D5BC52ED
Jika ada elektron yang bergerak
dengan kecepatan v dalam suatu
medan magnet B, arah gaya
Lorentznya mengikuti kaidah tangan
kanan.
200 Mudah dan Aktif Belajar Fisika untuk Kelas XII
( 9CDB9; #@1BD9;5
12. .
M
5D5B171
=E1D1 @1BD9;5 C91B ;1D?45
% =1CC1 @1BD9;5 C91B ;1D?45
. ;535@1D1 @1BD9;5 C91B ;1D?45
2541 @?D5C91 I17 4925B9;1
13. 5D9;1 @1BD9;5 C91B ;1D?45 D5D1@ 25B75B1; EBEC G11E@E 4925B9
=541 9CDB9; 41 =541 =175D 25B1BD9
18. –
muatan negatif
–
–
–
–
Fisika Atom 201
5C1B141 41@1D49;5D18E941B9@57E;EB1C589771*8?=C?
=541@1D;1@5B214971=E1D141=1CC1 %@1BD9;5C91B;1D?45
C521719 25B9;ED
%
$/64965 =51;E;1 5;C@5B9=5 99 25BE17E17 I19DE 4571
=5771D9 71C 411= @51D ;1D?45 4571 ECEB 19I1 41 =5771D9
71C411=C91B;1D?4599;1D5D1@981C9I174941@1D;1$/64965
D5D1@ C1=1 5=E491 $/64965 =5I9=@E;1 218G1 @1BD9;5 C91B
;1D?45 99 =5BE@1;1 2181 I17 141 49 C5D91@ J1D $/64965 =5=25B9
1=1@1BD9;599'*(-+$+D5D1@9@1BD9;599529849;5145711=1
$#,*'
%18 1@1;18 41 D18E =571@1 $/64965 =5I9=@E;1 218G1
55;DB? 99 21791 41B9 1D?= $571@1 91 D941; =5I9=@E;1 218G1
55;DB?99141181D?=1D1E4571;1D1191D?=25B=E1D1571D96
41 4E1 11C1 I17 =541C1B9 ;5C9=@E1 $/64965 I19DE C521719
25B9;ED
?C5@41C1BD5D171D?=I17=5I1D1;1218G11D?=9DE5DB1
19. )11D9DE69C9;1G1D518=575D18E9=1CC141B91D?=894B?75I17
=5BE@1;1 1D?= D5B971 41B9 5;C@5B9=5 D5D17 55;DB?9C9C
*5BI1D1 919 % :1E8 5298 ;539 C5;1B17 D518 D5B2E;D9 B1C9?I1
14118
41B9 =1CC1 1D?= 894B?75
D1C 41C1B 9DE18 $/64965 =57ECE;1 C52E18 =?45 1D?= I17
49;51 4571 =?45 1D?= ;E5 ;9C=9C I19DE C521719 25B9;ED
D?=25B25DE;2E1D@141D4571=E1D1@?C9D96D5BC521B;5C5EBE8
21791 2?1 D5BC52ED
20. $E1D1 @?C9D96 99 495DB1;1 ?58 =E1D1 571D96 I17 =55;1D
@141 @5B=E;11 2?1 D5BC52ED
525B81C91 $/64965 =55=E;1 C118 C1DE ;5@971 @EJJ5
1D?= 99 =5=25B9;1 9C@9B1C9 2179 69C9;1G1 19I1 =51;E;1
5;C@5B9=5D5D5C=9I1;I17491;E;1?586),8:03302(5C5?B17
69C9;1G1 41B9 =5B9;1 )5B9;1D ;C@5B9=5 D5D5C =9I1; $99;1 99
25B81C9 =541@1D;1 25C1BI1 =E1D1 41 =1CC1 41B9 55;DB? +DE;
5298 :51CI1 C918;1 41 @5B81D9;1 (4)(8 25B9;ED
pengamat
mikroskopis
P
;7 M
minyak disemprot
lubang kecil
radiasi sinar-X
pelat negatif
tetes minyak
Sumber: Chemistry, 2001
)5@5BD9 49@5B981D;1 @141 (4)(8 03302(5 25B5;C@5B9=5
4571 =5I5=@B?D;1 =9I1; ;5 411= C52E18 D12E7 1D1E ;?D1;
?D1; D5BC52ED =5=99;9 4E1 @51D 25B=E1D1 I19DE @51D @?C9D96 @141
21791 1D1C 41 @51D 571D96 @141 21791 21G18 $9I1; I17
49C5=@B?D;1D5BC52ED@141217911D1C@51D@?C9D96=5=25DE;D5D5C1
–
–
Gambar 8.2
Model Atom Thomson
Gambar 8.3
Percobaan tetes minyak Millikan
21. ;1B51 @571BE8 71I1 25B1D *5D5C1 D5BC52ED :1DE8 ;5 21G18 =55G1D9
C52E18 E217 ;539 @141 @51D @?C9D96 9 C99 D5D5C1 =9I1; 49C91B9
4571 C91B. CE@1I1 D5D5C1 D5BC52ED 25B=E1D1 571D96 58 ;1B51
@51DD5BC52ED25E=4925B9=E1D1D5D5C1=9I1;D5BC52EDD5BEC25B75B1;
;5 21G18
)519 71I1 25B1D @141 D5D5C1 =9I1; D5BC52ED 25;5B:1 :E71 71I1
)D?;5C 41 71I1 B389=545C 971D ;5=219 =1D5B9 D5D17 6E941 49
51C . !149 C531B1 =1D5=1D9C 41@1D 49DE9C;1 C521719 25B9;ED
Felektrostatis
FA
mg
202 Mudah dan Aktif Belajar Fisika untuk Kelas XII
% -
*. M
58 ;1B51 D5D5C1 =9I1; 491CE=C9;1 25B25DE; 2?1 !,89(4((5
@
41@1D 49DE9C;1 =5:149
%
*
* -
*. M
5D5B171
%
=1CC1 :59C =9I1;
-
=1CC1 :59C E41B1
* :1B9:1B9 D5D5C1 =9I1;
. F?E=5 D5D5C1 =9I1;
F9C;?C9D1C E41B1
-11E@E 141 71I1 )D?;5C 41 71I1 B389=545C D5D5C1 =9I1;
D5D1@25B75B1;;521G18;1B5171I125B1DI1529825C1B)525E=D5D5C1
=9I1;D5BC52EDC1=@1949@51D571D962541@?D5C91491;D96;1C589771
=E3E71I155;DB?CD1D9C;51D1C1D1B1D5D5C1=9I1;41@51D@?C9D96
!9;1 2541 @?D5C91 491DEB CE1DE C11D 1;1 D5B:149 ;5C5D9=2171 1D1B1
71I1 25B1D 71I1 B389=545C 41 71I1 55;DB?CD1D9C 14118
% -
) M
571=5759=91C9;1!,89(4((5@
41!,89(4((5@1;1
4941@1D;1
)M *.
M
)
* .
M
5D5B171
) =E1D1 @1BD9;5
F9C;?C9D1C
. ;535@1D1 D5D5C1 =9I1;
=541 9CDB9;
11=5;C@5B9=5I1 03302(5 =57E;EB 17CE7 25C1BI1 41
. D5D1@9 EDE; =541@1D;1 919 F9C;?C9D1C 03302(5 =51;E;1
5;C@5B9=5 D5B@9C18
$5EBED @541@1D 41 1@1;18 =E1D1 @1BD9;5 ) 29C1 17CE7
4941@1D;1 4571 =577E1;1 !,89(4((5 @ 5411 I17 49
8141@9 EDE; =577E1;1 !,89(4((5@ 14118 @1:17 :1B9:1B9 *
41B9 D5D5C1 =9I1; D941; 41@1D 49E;EB 17CE7 '1:17 :1B9:1B9 D5D5C1
=9I1; 41@1D 49;5D18E9 4571 =577E1;1 !,89(4((5 @
FS
FA
mg
Gambar 8.4
Gaya berat, gaya Archimedes, dan
gaya stokes bekerja pada tetesan
minyak pada percobaan Millikan.
Gambar 8.5
Tetesan minyak berada dalam
kesetimbangan karena adanya
gaya berat, gaya Archimedes, dan
gaya elektrostatis.
Tugas Anda 8.1
Dengan menggunakan logika dan
pemahaman Anda tentang konsep
gerak lurus, apakah Anda dapat
menduga bagaimana Millikan
mengukur kecepatan (v) dari
tetesan minyak tersebut? Jelaskan
dengan alasan-alasan ilmiah
menurut pendapat Anda.
23. .
% -
M
)E2CD9DEC9;1!,89(4((5@ ;5!,89(4((5C5897714941@1D;1
)
25. % -
.
M
58 ;1B51 - %
!,89(4((5 @ 41@1D 49DE9C;1=5:149
)
28. )5D518 =57E17 5;C@5B9=5 D5BC52ED 2525B1@1 ;19 03302(5
=541@1D;1 ;5C9=@E1 C521719 25B9;ED
5C1BI1 =E1D1 D5D5C1 =9I1; D941; @5B18 25B919 5298 ;539
41B9
33. P
M
1B9 ;5C9=@E1 99 4941@1D;1 81C9 218G1 =E1D1 55;DB?
14118
35. P
MP
M
41 =1CC1I1 14118
P
;7
%
%
P
P
M
;7
4. Model Atom Rutherford
*5?B9 1D?= *8?=C? @141 49E:9 ?58 C5?B17 69C9;1G1 1C1
77B9C85,9:;:/,8-68+ 1=57E:9;5251B1D5?B9*8?=C?4571
=51;E;1@5B3?211=577E1;1@1BD9;5161I1749D5=21;;1@141
C52E18 ;5@97 ?71= 5=1C I17 C171D D9@9C '1BD9;5 161 14118 @1BD9;5
I17 49@131B;1 ?58 ECEB B149?1;D96 25B=E1D1 9CDB9; @?C9D96 I17
25C1BI14E1;19=E1D155;DB?41=1CC1I15=@1D;19=1CC1@B?D?
);5=1 @5B3?211 (ED85B6?B4 41@1D 41 981D @141 (4)(8
sumber partikel alfa
beberapa partikel
alfa dipantulkan kembali
keping tipis emas
pancaran
alfa
sebagian partikel
alfa dibelokkan
layar detektor
sebagian partikel alfa
menembus keping logam
Gambar 8.6
Percobaan Rutherford
Tokoh
Ernest Rutherford
(1871–1937)
Ernest Rutherford lahir di New
Zealand pada 1871. Ia mendapat
beasiswa di Universitas Cambridge,
Inggris pada 1894. Di sana, ia mulai
melakukan penelitian tentang radiasi
elektromagnetik, tetapi kemudian
perhatiannya beralih ke sinar-X dan
radioaktivitas. Ia menunjukkan bahwa
ada perbedaan tipe radioaktivitas,
yang ia namakan radiasi alfa, beta, dan
gamma. Ia mendapat hadiah Nobel
untuk bidang kimia pada 1908. Pada
1911, Rutherford menjadi seorang
profesor di Universitas Manchester, ia
menemukan bahwa hampir seluruh
massa atom berkumpul di inti atom.
36. partikel alfa
inti
atom
dibelokkan
menembus
dipantulkan
;:/,8-68+ =5=99;9 1CE=C9 218G1 :9;1 D5?B9 1D?= *8?=C? 251B
C5EBE8 @1BD9;5 161 4571 55B79 I17 25C1B 81BEC =55=2EC EBEC
;5@97 D9@9C 5=1C D5BC52ED ;1B51 1D?=1D?= ;5@97 ?71= 5=1C 5DB1
D941; =5781179 @1BD9;5 161 I17 25B=E1D1 9CDB9; @?C9D96 )5D518
491;E;1 2525B1@1 ;19 @5B3?211 49C9=@E;1 218G1 C521791 25C1B
@1BD9;5 161 =55=2EC ;5@97 ?71= D9@9C EBEC =57519 1I1B ;1
D5D1@9 2525B1@1 @1BD9;5 161 I17 19I1 4925?;;1 218;1 141 I17
49@1DE;1)5D91@CE4ED@5=25?;141@5=1DE1C91B161D5BC52ED
49E;EB 4571 D59D9 ?58 ;:/,8-68+
1;D1 99 ;5=E491 49119C9C ?58 ;:/,8-68+ C521719 25B9;ED
5B41C1B;1E;E=?E?=2@1BD9;5161I1725B=E1D1@?C9D9681I1
1;1 4925?;;1 1D1E 49@1DE;1 ?58 CE1DE =E1D1 C5:59C I19DE
=E1D1@?C9D96BD9I1411=1D?=?71=5=1C81BEC141=E1D19CDB9;
@?C9D96 41 D941; D5BC521B 49 C5EBE8 1D?= =519;1 D5B@EC1D 49 CE1DE
D5=@1D C589771 =5?1; @1BD9;5 161 D1C 41C1B 61;D1 99 ;:/,8-68+
25B;5C9=@E1 C521719 25B9;ED
1 $E1D19CDB9;1D?=41C52179125C1B=1CC11D?=D5B@EC1D49CE1DE
D9D9; I17 49C52ED ?58 ;:/,8-68+ C521719 9D9 1D?= D9 1D?= 99
=5BE@1;1 CE1DE 415B18 I17 C171D ;539 4571 491=5D5B C5;9D1B
M=
2 '141:1B1;I17B51D96:1E841B99D91D?=D5BC52ED@1BD9;525B=E1D1
571D96 1D1E 55;DB? 25B541B =5759979 9D9$E1D1 9CDB9; @?C9D96
I1725B@EC1D499D91D?=919I1C1=125C1B4571:E=18=E1D1
9CDB9; 571D96 41B9 55;DB?55;DB? I17 =5759979I1
$5C;9@E 5298 219; 41B9@141 D5?B9 !! *8?=C? 1=E D5?B9 1D?=
(ED85B6?B4 =1C98 =5I9=@1 ;55=181 55=181 D5?B9 1D?=
(ED85B6?B4 14118 C521719 25B9;ED
*5?B9 1D?= (ED85B6?B4 D941; 41@1D =5:51C;1 C@5;DBE= 3181I1
I17 49@131B;1 ?58 1D?= 894B?75 ;5D9;1 71C 894B?75 D5BC52ED
49@11C;1 1D1E 49=1CE;;1 ;5 411= D12E7 41 4925B9 2541
@?D5C91 9CDB9; I17 D9779 1D1B1 E:E7E:E7 D12E7 D5BC52ED
37. *5?B9 1D?= (ED85B6?B4 D941; 41@1D =5:51C;1 ;5CD1291 1D?=
5B41C1B;1 E;E= ?E?=2 55;DB? I17 25B9D5B1;C9 4571
9D91D?=1;1=5711=971I1?E?=2I17:E7125B6E7C9C521719
71I1 C5DB9@5D1 ;921DI1 55;DB? =5711=9 @5B35@1D1
@5B35@1D1 C5DB9@5D1 $5EBED D5?B9 75?=217 55;DB?=175D9;
I1749;5=E;1;1?58(=,33:9;1=E1D155;DB?=5711=9
@5B35@1D1 =E1D1 D5BC52ED 1;1 =5=131B;1 75?=217
55;DB?=175D9; !9;1 45=9;91 55B79 55;DB? 25B;EB17 41
1;89BI1 1;1 :1DE8 D5BD1B9; ;5 9D9 1D?=
5. Spektrum Atom Hidrogen
)E1DE71CI1749=1CE;;1;5411=D12E741;54E1E:E7D12E7
D5BC52ED 4925B9 2541 @?D5C91 9CDB9; I17 D9779 1;1 =5=131B;1
3181I1 5D9;1 71C 894B?75 49=1CE;;1 411= D12E7 @5E3ED1 71C
;5=E491491E9?58C91B;1D?45=1;171C894B?751;1=5=131B;1
3181I1 181I1 99 ;5=E491 49119C9C ?58 +(#,*'%,* I19DE C52E18
11D EDE; =5981D 41 =5=?DB5D C@5;DBE= 3181I1 C5;197EC =57E;EB
@1:17 75?=217I1 5B9;ED 99 14118 C@5;DBE= 3181I1 @141 415B18
D1=@1; I17 49@131B;1 ?58 71C 894B?75
Skema penyimpangan sinar alfa.
inti atom
elektron
Gambar 8.7
Gambar 8.8
Model atom Rutherford
204 Mudah dan Aktif Belajar Fisika untuk Kelas XII
38. Fisika Atom 205
warna
frekuensi (Hz)
)5?B17 7EBE C5;?18 =55718 25B;5217C11 )G5491 6/(55,9
(34,8 =531D1D 218G1 ;5?=@?; @1:17 75?=217 C@5;DBE= 71B9C
@131B 894B?75 411= 415B18 D1=@1; 41@1D 493?3?;;1 C531B1 D5@1D
4571 BE=EC C521719 25B9;ED
40. M
Keterangan:
29171 I17 25B919 =E19 41B9
# ;?CD1D1
=
@1:17 75?=217 =
!,89(4((5 @ 49;51 C521719 BE=EC 1=5B 41 45B5D1 71B9C
C@5;DBE= I17 3?3?; 4571 @5BC1=11 D5BC52ED 491=1;1 45B5D
1=5B ?+),8. ;5=E491 =55=E;1 BE=EC C5BE@1 @141 ECEB 1;19
#9 %1 41 C 5B5D 1=5B EDE; C@5;DBE= 894B?75 49DE9C 411=
29171 75?=217 .
9171 75?=217 EDE; 45B5D 1=5B
45B5D 3181I1 D1=@1; 14118
4571 53. merah biru ungu
4 × 1014 5 × 1014 6 × 1014 7 × 1014 8 × 1014
Gambar 8.9
Spektrum hidrogen pada daerah
tampak
Tantangan
untuk Anda
Diskusikanlah bersama teman Anda,
apakah Anda dan teman Anda dapat
menduga mengapa dalam
eksperimennya Rutherford
menggunakan sinar dan lempeng
emas?
Tantangan
untuk Anda
Hitunglah panjang gelombang
terpendek dan terpanjang untuk
deret Balmer, deret Lyman, deret
Pascha, deret Bracket, dan deret
Pfund.
Sumber: Konsep Fisika Modern, 1983
58. =
=
K
m
206 Mudah dan Aktif Belajar Fisika untuk Kelas XII
61. =
6. Model Atom Bohr
)5D518;:/,8-68+=575=E;1;1218G1=1CC141=E1D1@?C9D96
1D?= D5B89=@E @141 CE1DE 415B18 ;539 49 @EC1D 1D?= 69C9;1G1 1C1
5=1B; 0,39 6/8 @141
=575=E;1;1 218G1 CDBE;DEB 1D?=
=9B9@ 4571 C9CD5= D1D1 CEBI1 D9 1D?= 25B141 49 @EC1D C9CD5= 1D?=
4155;DB?25B141@1419D1C1D5BD5DEI1749C52ED;E9D1D?=+DE;
=57E1D;1D5?B91D?=I1749ECE;1I16/8=5IECE4E1@?CDE1D
419 D5D17 1D?=
'?CDE1D @5BD1=1
11=CE1DEC9CD5=1D?=55;DB?D941;=5=131B;1B1491C9;5D9;1
91 =57?B29D 9D9 1D?= #9D1C19D1C1 55;DB? =57?B29D D1@1
=5=131B;1 B1491C9 491=1;1 9D1C1 CD1C9?5B 1D1E ?B29D CD1C9?5B
'?CDE1D 99 25B1G11 4571 D5?B9 55;DB?=175D9; ;1C9;
62. '?CDE1D ;54E1
'5=131B141@5I5B1@175?=21755;DB?=175D9;411=CE1DE
1D?= 25B8E2E71 4571 DB1C9C9 55;DB? 41B9 4E1 9D1C1 CD1C9?5B
+DE; C545B811I1 @5B81D9;1 (4)(8 $?45 1D?= ?8B
EDE; 1D?= 894B?75 =5=@5B981D;1 218G1 C52E18 55;DB? =579D1B9
C52E18 9D9 1D?= 25B=E1D1 @?C9D96 !1B9:1B9 ?B29D 97;1B1I1 * 41
55;DB? 25B=1CC1 % 25B75B1; 4571 1:E 951B D5D1@ . 1I1 D1B9;
?E?=2 25B@5B1 =5=25B9;1 @5B35@1D1 C5DB9@5D1 C589771
70. * * * *
58 ;1B51 EDE; 1D?= 894B?75 @5BC1=11 D5BC52ED =5:149
74. * * *
5B79;95D9;55;DB?14118
79. *
M
Gambar 8.10
Model atom Bohr (Z = 1) untuk
hidrogen
v
F
r
inti
elektron
+Ze
80. Sumber: Jendela Iptek, 1997
Fisika Atom 207
41@E 55B79 @?D5C91 55;DB? 14118 55B79 @?D5C91 ?E?=2 I17
25C1BI1 C521719 25B9;ED
81. M
(
*
C589771 55B79 D?D1 I17 49=99;9 ?58 55;DB? 14118
86. =E1D1 9CDB9;
* :1B9:1B9 9D1C1 =
a. Jari-Jari Lintasan Stasioner
9C9;1 ;1C9; =5B1=1;1 218G1 C52E18 =E1D1 55;DB9; I17
=5711=9@5B35@1D1C5@5BD955;DB?I17=57?B29D411==?451D?=
81BEC =5B1491C9;1 55B79 55;DB?=175D9; C531B1 ;?D9E 5D9;1 55B79
99 49@131B;1 55B79 D?D1 55;DB? =5EBE 41 55;DB? 1;1
25B75B1; C@9B1 =5E:E 9D9 1D?= C589771 1D?= 1;89BI1 :1DE8 ;5 9D9
1D?= +DE; =571D1C9 ;5CE9D1 99 6/8 =57ECE;1 7171C1 ?B29D
CD1C9?5B@?CDE1D@5BD1=11B9C996/8=5I9=@E;1218G1411=
;51411 99 =?=5DE= CE4ED ?B29D1 55;DB? 25B919 ;59@1D1 41B9
81B71 88. ,5;D?B =?=5DE= CE4ED 411= 69C9;1 ;1C9; 4945699C9;1 C521719
+DE;=?=5DE=CE4ED55;DB?I1725B541B=5759979
9D9 1D?= * D571; EBEC ( C589771 @5BC1=11 =?=5DE= CE4ED 41@1D
49C545B811;1 =5:149 *( %.* !149 =5EBED @?CDE1D ?8B
=?=5DE= CE4ED 14118
%. * M
5D5B171
291712E1D 105. Tokoh
Niels Bohr
(1885–1962)
Pada awal 1900-an, struktur atom
menjadi lebih jelas, namun hukum
Fisika pada saat itu tidak dapat
menjelaskan mengapa elektron
tidak cepat menghasilkan spiral
menuju inti. Niels Bohr, murid
Rutherford, membantu memecah-kan
misteri itu dengan menunjukkan
bahwa elektron-elektron hanya
diberi energi tertentu. Ia
menemukan bahwa elektron-elektron
yang memiliki energi
terendah mengorbit paling dekat ke
inti, dan elektron dengan energi
tinggi mengorbit paling jauh. Pada
1913, Niels Bohr juga menjelaskan
hubungan antara materi dan cahaya.
Ia menunjukkan bahwa jika elektron
berpindah dari satu tingkat energi
ke tingkat energi lainnya, elektron-elektron
itu mengeluarkan atau
menyerap paket radiasi dalam
bentuk cahaya. Paket ini dinamakan
foton.
106. 1B9 !,89(4((5 @
41@1D 49@5B?58 :1B9:1B9 55;DB? I17
49@5B;51;1 EDE; C5D91@ 9D1C1 5C1B1 ? 4945699C9;1 C521719
:1B9:1B9?8B+DE;1D?=894B?756/8=541@1D;181B71?
109. ?41C5D5BECI1!1B9
:1B9 1D?= =5EBED D5?B9 99 D941; @5B18 25B919
? 1D1E ?
b. Energi Elektron Berdasarkan Teori Bohr
5C1B 55B79 55;DB? 41@1D 49@5B?58 4571 =57712E7;1
!,89(4((5 @ 41 !,89(4((5 @
I19DE
E = 0
E
n
=
13,6 eV
3
208 Mudah dan Aktif Belajar Fisika untuk Kelas XII
115. '5BC1=11 99 =5I1D1;1 218G1 55B79 55;DB? D5B;E1D9C1C9
BD9I1 81I1 919919 55B79 D5BD5DE I17 49@5B;51;1 !9;1 41B9
@5BC1=11 D5BC52ED C5=E1 919 D5D1@I1 4989DE7 4941@1D @5BC1=11
I17 5298 C545B811 C5@5BD9 25B9;ED
5,
M 118. L *97;1D 55B79 55;DB? @141
;51411 I17 5298 D9779 49DE:E;;1 @141 (4)(8
'14155;DB?419D91D?=I17D5B@9C18C171D:1E8I19DEEDE;
49@5B?58
!9;155;DB?9DE25BDB1C9C91D1E25B@941841B9
9D1C1 E1B ;5 9D1C1 411= C589771 91 25B141 @141 ?B29D D5BD5DE
411= 9D1C1 D5BD5DE 55;DB? 1;1 =5=99;9 81B71 55B79 5298
;539 41B9@141 ;51411 C5=E1
'141 ;51411 D5BC52ED 1;1
49@131B;1 55B79 C525C1B )5219;I1 :9;1 55;DB? @141 ;51411
55;DB?I1 41@1D 492521C;1 41B9 9;1D1 9D9 4571 =5=25B9I1
55B79 C525C1B 5B79 99 49;51 4571 55B79 9;1D ;51411 !9;1
55B79 I17 492521C;1 =552989 55B79 9;1D ;552981 55B79 41@1D
=E3E C521719 55B79 ;95D9; 55;DB? I17 ;99 D518 2521C 41 D941;
D5B9;1D 179 @141 9D9 1D?=
?8B=5=@?CDE1D;1218G1=5C;9@E55;DB?D941;=5=131B;1
B1491C9 55;DB?=175D9; ;5D9;1 25B541B @141 CE1DE D97;1D D5BD5DE
55;DB? 41@1D 25B@9418 41B9 CE1DE ;51411 55B79 D5BD5DE ;5 ;51411
55B79 I17 19 )59C98 55B79 1D1B1 4E1 ;51411 D5BC52ED =E3E
C521719 C52E18 B1491C9 75?=217 55;DB?=175D9; 25B55B79 BD9I1
:9;155;DB?25B@941841B9;514111G1;5;514111;89B1;1D5B:149
@131B1 1D1E @5I5B1@1 B1491C9 55;DB?=175D9; B5;E5C9 75?=217
55;DB?=175D9; I17 49C5B1@ 1D1E 49@131B;1 41B9 4E1 ;51411
CD1C9?5B 14118
! M 120. P
M
!C
55B79 1;89B !
6B5;E5C9 B1491C9 75?=217 55;DB?=175D9; J
Gambar 8.11
Tingkat-tingkat energi atom
hidrogen.
n
n = 4
n = 3
n = 2
E = –0,8 eV
E = –1,5 eV
E = –3,4 eV
n = 1 E = –13,6 eV
Pembahasan Soal
Dalam model atom Bohr, energi
yang dibutuhkan oleh elektron
hidrogen untuk pindah dari orbit
dengan bilangan kuantum 1 ke 3
adalah ....
a. 1,50 eV
b. 1,90 eV
c. 2,35 eV
d. 12,10 eV
e. 13,60 eV
UMPTN 1992
Pembahasan:
Energi yang dibutuhkan
E = E3 – E1
Diketahui bahwa energi dasar = E1
= –13,6 eV
Maks,
E3 = 1
2
2
Jadi,
E =
13,6 eV
9
– (– 13,6 eV)
= 12,10 eV
Jawaban: d
121. Contoh 8.2 Kata Kunci
Fisika Atom 209
9DE718;535@1D155B79;95D9;55B79@?D5C914155B79D?D155;DB?@141
29171;E1DE=
25B41C1B;1D5?B9?8BEDE;1D?=894B?75
(=()
9;5D18E9
% P
M
;7
P
M
!C P
M
*
P
M
= # P
%= 135. %=
!
#
(
*
=
4 5B79D?D155;DB?4981C9;1=51E9@5BC1=11
#(
137. P
M!
• model atom Demokritus
• model atom Dalton
• Hukum Perbandingan Tetap
• Hukum Lavoisier
• model atom Thomson
• tetes minyak Millikan
• model atom Rutherford
• model atom Bohr
• jari-jari Bohr
• orbit stasioner
• energi elektron terkuantisasi
Tantangan
untuk Anda
Jika sebuah atom terdiri atas
beberapa atom, apakah ada gaya
elektrostatik antarelektron
tersebut? Kemudian, bagaimana
lintasan orbit elektron tersebut?
Contoh 8.3
!9;1:1B9:1B955;DB?I1725B75B1;@1419D1C1CD1C9?5B*L25B1@1;18
;51:E155;DB?D5BC52ED
9;5D18E9=1CC141=E1D1I1%P
M
;741P
M
!1G12
51:E155;DB?.4981C9;14571=577E1;1@5BC1=11
146. = C
;7
=
%*
!149;51:E155;DB?D5BC52ED14118 147. P
= C
Contoh 8.4
)52E1855;DB?@1411D?=894B?7525B@941841B955B795;C9D1C9;5
5B1@1;186B5;E5C9@131B16?D?I1
(=()
9;5D18E9 152. !
B. Atom Berelektron Banyak
1. Kelemahan Teori Atom Bohr
5B17;1 41C1B D5?B9 1D?= ?8B C5251BI1 =5713E ;5@141 =?45
1D?= (ED85B6?B4
525B1@1 ;55=181 D5?B9 1D?= ?8B I17 41@1D 49C5=@EB1;1
C589771 41@1D =5I97;1@ =9CD5B9 D5D17 1D?= 14118 C521719 25B9;ED
*5?B9 1D?= ?8B D941; 41@1D =5:51C;1 C531B1 B939 D5D17 71B9C
C@5;DBE= *5BED1=1 @5B25411 @1:17 75?=217 41 9D5C9D1C
71B9C C@5;DBE= D5BC52ED
153. !E=18 55;DB? I17 D5B921D 411= 1D?= 81I1 C1DE 55;DB?
C589771 EDE; 1D?= 25B55;DB? 21I1; D941; 41@1D 497E1;1
179 ?D?8I1 1D?= 894B?75 =5=99;9 C1DE 55;DB? 41 71I1
55;DB?CD1D9C I17 141 81I1 71I1 D1B9;=51B9; 1D1B1 9D9 1D?=
41 55;DB? 41@E EDE; 1D?= I17 =5=99;9 5298 41B9 C1DE
55;DB? C519 71I1 D1B9;=51B9; =1C98 141 71I1 D?1; 1D1B1
55;DB? I17 C1DE 41 55;DB? I17 19 6/8 =571219;1 71I1
D?1; 99
D?=1D?= 25B712E7 =5=25DE; J1D 1D1E =1D5B9 D5B1;C9 1D1B
1D?= =5I5212;1 C961DC961D I17 25B2541 1D1B1 ECEB I17 C1DE
41ECEBI1719'5I5212@5B25411C961DC961DD5BC52EDD5BI1D1
D941; =1=@E 49D5B17;1 ?58 D5?B9 1D?= ?8B
210 Mudah dan Aktif Belajar Fisika untuk Kelas XII
155. J
$571@1 $/64965 29C1 =5I9=@E;1 218G1
55;DB?=5BE@1;12179141B91D?=
156. !51C;1 ;55=181;55=181 411= D5?B9 1D?=
(ED85B6?B4
9DE7 @1:17 75?=217 6?D? D5B@545; 41
D5B@1:1741B945B5D1=5B1D?=894B?75
9DE7@1:1775?=2176?D?I1749@131B;1
1;921D DB1C9C9 41B9 ;5
DB1C9C9 ;5
=5BE@1;145B5D'1C385
1B9 29171 ;E1DE= ;5 25B1@1;18 DB1C9C9 I17
=5781C9;1@1:1775?=217
157. L41B945B5D
#I=1
1B929171;E1DE=;525B1@1;18DB1C9C9I17=57
81C9;1@1:1775?=217L41B945B5D1=5B
9DE7;535@1D155B79;95D9;55B79@?D5C9141
55B79D?D155;DB?@141?B29D;5?8BEDE;1D?=
894B?75
*5DE;118@1:1775?=2176?D?I1749C5B1@
1D?=894B?75:9;155;DB?25B5;C9D1C941B9;5
D97;1D 161. Fisika Atom 211
$?451D?=?8B=51771B@B9C9@;5D941;@1CD91I1749;5=E;1;1
?58 ,09,5),8.
11= =571D1C9 ;5;EB171 D5BC52ED 2525B1@1 69C9;1G1 C5@5BD9
6;09 +, 86.30, 63-.(5. !(;30 8=05 #*/86+05.,8 41 (85,8
,09,5),8. =5=@5B;51;1 =5;19;1 75?=217 1D1E =5;19;1
;E1DE= EDE; =5771=21B;1 ;51411 55B79 55;DB? 411= 1D?=
2. Bilangan Kuantum
5;DB?55;DB? 25B75B1; =5759979 9D9 41 49;5?=@?;;1 ;5
411= ;E9D;E9D $5EBED D5?B9 1D?= ?8B EDE; =5I1D1;1 @?C9C9
55;DB?81I149@5BE;1C1DE!$#-,-%I19DE29171;E1DE=
ED1=1 5B2541 4571 D5?B9 1D?= =5;19;1 ;E1DE= @141 D5?B9 99
55;DB?411=CE1DE1D?=4971=21B;1411=5=@1D29171;E1DE=
I19DE
29171 ;E1DE= ED1=1 C9=2?
162. 29171 ;E1DE= ?B29D1 C9=2?
29171 ;E1DE= =175D9; C9=2? %
29171 ;E1DE= C@9 C9=2? %C
a. Bilangan Kuantum Utama (n)
9171 ;E1DE= ED1=1 =5I1D1;1 25C1B 55B79 D?D1 411=
;E9D 1D?= 1 99 25B1BD9 EDE; =575E1B;1 55;DB? 41B9 ?B29DI1
49@5BE;1 C5:E=18 55B79 5B79 D5B5418 49=E19 41B9 ;E9D
;5=E491 ;E9D # $ % 41 C5D5BECI1 D?= 894B?75 =5=99;9
55B79 D?D1 C5CE19 4571 @5BC1=11
5,
M 163. +DE; 9? 5 I17 81I1 =5=99;9 C52E18 55;DB? 4571 0 167. 5B79 D?D1 55;DB? 411= 1D?= 14118 ;?CD1 41 ,*#-,!++!
?58 29171 ;E1DE= 9171 ;E1DE= ED1=1 =5=99;9 919 175. Informasi
untuk Anda
Information for You
Gambar 8.12
Bentuk-bentuk orbital
(a) Orbital s merupakan sebuah bola;
(b) Orbital p memiliki bentuk
seperti balon yang terpilin dua;
(c) Orbital d memiliki bentuk
seperti empat buah balon yang
terpilin.
Contoh 8.5
D?==5=99;955;DB?*5DE;114125B1@1;E9D4125B1@155;DB?@141
C5D91@;E9D
(=()
5B41C1B;1;?697EB1C955;DB?BE=EC 178. !149@1411D?='D5B41@1D
;E9DM#M$
b. Bilangan Kuantum Orbital ( )
41D518=575D18E9218G155;DB?25B?D1C9=579D1B99D91D?=
@141 ?B29DI1 9171 ;E1DE= ?B29D1 =5I1D1;1 =?=5DE= CE4ED
55;DB? I17 25B?D1C9 D5B8141@ @?B?C 9D9 1D?= $51E9 @5BC1=11
*'!* 25C1B =?=5DE= CE4ED 55;DB? 14118
P
M
!C
Contoh 8.6
212 Mudah dan Aktif Belajar Fisika untuk Kelas XII
M 180. %919 25B71DE7 @141 919 29171 ;E1DE= ED1=1 I19DE =E19
41B9 ? C1=@19 4571 M 1D1E 49I1D1;1 C521719
181. M
)5D91@ ?B29D1 =5=99;9 1=1 41 25DE; D5BD5DE %1=1 ?B29D1 I17
49I1D1;1 ?58 919 14118
491=1;1 CE2;E9D + + *(
491=1;1 CE2;E9D ( (*!!($
182. 491=1;1 CE2;E9D !-+
491=1;1 CE2;E9D -%,$
(4)(8
=5=@5B981D;1 25DE; C5D91@ ?B29D1 9171 ;E1DE=
?B29D1 :E71 C5B97 49C52ED 4571 29171 ;E1DE= 1J9=ED
1 2 3
*5DE;1=?=5DE=CE4ED55;DB?EDE;
P
M
!C
(=()
571=577E1;1!,89(4((5@
=1;1
!C
184. P
M
!C
Atom adalah partikel yang sangat
kecil sehingga tidak dapat diamati
dengan cahaya tampak.
Menggambarkan struktur atom
merupakan pekerjaan yang sangat
menarik. Untuk mempelajari atom,
para ahli mempelajarinya dari cahaya
yang diesensikan oleh atom-atom
dari unsur murni. Spektrum cahaya
tersebut mengandung informasi
tentang struktur, atom, energi
ionisasi, dan lain-lain.
Atom are tiny, and not observable
using visible light. Trying to figure out
the structure of atoms is a facinating
task. A major source of information
about atoms comes from a study of
the light emitted by the atoms of a
pure material. The spectrum of the
light give information about atom
structure, ionization energy, etc.
186. = 2
Fisika Atom 213
%1=1
+ ( !
CE2;E9D
51411 =?=5DE= CE4ED ?B29D 55;DB? 491=1;1 4571 CE2;E9D
I19DE CE2;E9D + EDE; ;51411
CE2;E9D ( EDE; ;51411
CE2;E9D EDE; ;51411 187. 41 C5D5BECI1 '5B81D9;1 $(),3
5C1BI1=?=5DE=CE4ED?B29D155;DB?EDE;45B5D@5BD1=1I17
25B1C1 41B9 C@5;DBE= I19DE 45B5D + + *( ( (*!!($ !-+ 41
-%,$ 14118
)E2;E9D +
25C1B =?=5DE= CE4EDI1
195. 12E71 29171 ;E1DE= ED1=1 4571 29171 ;E1DE=
?B29D1 291C1I1 497E1;1 EDE; =5I1D1;1 ;51411 55;DB?
411= CE1DE 1D?= $9C1I1 199. 55;DB?
411=CE2;E9D(1411855;DB?CE2;E9D14118
55;DB?CE2;E9D
14118 55;DB? 41 C5D5BECI1 C5@5BD9 $(),3
c. Bilangan Kuantum Magnetik (m )
58 ;1B51 55;DB? 25B=E1D1 9CDB9; 75B1; 55;DB? 41@1D
49@571BE89 ?58 =541 =175D9; ;921DI1 55;DB? I17 25B75B1;
49 411= ?B29DI1 =5=99;9 =?=5 =175D9; $?=5 =175D9; 41B9
55;DB? 99 49I1D1;1 4571 29171 ;E1DE= =175D9; =
9171 ;E1DE= =175D9; =5I1D1;1 1B18 =?=5DE= CE4ED
55;DB?!9;149D5D1@;11B18=541=175D9;E1BC5:1:1B4571CE=2E
0 ;5=E7;91 411= 1B18 0 49I1D1;1 4571 @5BC1=11
%
M 201. 9171 ;E1DE= =175D9; = =5=99;9 919 1D1B1 M 41
$9C1I1
EDE;
81B71=
1D1ED5B41@1D?B29D1
EDE; 81B71= M
411D1ED5B41@1D
?B29D1
EDE; 207. P21I1;=
2
0
–
–2
m = 2
m = 1
m = 0
m = 1
m = 2
Lz
Gambar 8.13
Arah dan besar momentum sudut
Lz untuk = 2
208. '141 (4)(8 49@5B981D;1 F5;D?BF5;D?B =?=5DE= CE4ED
4571 29171 ;E1DE= ?B29D1 D5BD5DE 9171 ;E1DE= =175D9;
:E71 =5771=21B;1 ;53545BE71 ;54E4E;1 ?B29D1 49 411= BE17
C5@5BD9 D5B981D @141 (4)(8 209. h
Z 2
h
h
Z
Z 2
Z 0
Z 0
h
Z 2
h
Z 2
Z
1 2 3
h
Gambar 8.14
Arah momentum sudut-sudut
orbital s, p, dan d
(a) orbital hanya memiliki 1
kemungkinan arah;
(b) orbital p memiliki 3
kemungkinan; dan
(c) orbital d memiliki 5
kemungkinan.
s
px py pz
dxy dxz dyz dx2y2 dx2y2
1 2
S h
S h
d. Bilangan Kuantum Spin (ms)
9171 ;E1DE= C@9 %C =5I1D1;1 1B18 @5B@ED1B1 55;DB?
D5B8141@ CE=2EI1 C@9 I17 41@1D =59=2E;1 =?=5 =175D9;
%91929171;E1DE=C@91414E1I19DE%C
M 210. (4( 6:(90 03(0?(5.07,82,5(52(5
214 Mudah dan Aktif Belajar Fisika untuk Kelas XII
z
z z
Z 0
0
1 2
Gambar 8.15
Elektron dalam subkulit s, p, dan d.
3
Gambar 8.16
Arah perputaran dan vektor
momentum sudut S.
1
2
1
2
Z 4
p
Z 4
p
S
$(),3 222. EDE; 1B18 @ED1B1 55;DB? ;5 ;9B9
$1C97=1C97 49DE9C 4571 ?D1C9 1B18 @118 ;5 1D1C 41 ;5 21G18
)E2;E9D + =5=99;9 C52E18 ?B29D1 41 @197 21I1; 499C9 4E1 55;DB?
)E2;E9D ( =5=99;9 D971 ?B29D1 (H (I (J 41 @197 21I1; 499C9 ?58
226. B18 =?=5DE= CE4ED 49D5DE;1 ?58 ;?=@?5 F5;D?B @141 CE=2E0
I19DE CE=2E D571; @141 C9CD5= ;??B491D D971 49=5C9
231. Tantangan
untuk Anda
Tentukan besar momentum sudut
untuk subkulit:
a. f;
b. g;
c h.
Z
Lz = me
Z
Fisika Atom 215
+DE;2E18% 49D5=@1D9?58 235. 41
41C5D5BECI1
*518 41 ;5D18E9 218G1 29171 ;E1DE= =175D9; 5B1D
8E2E71I1 4571 =541 =175D9; I17 49D9=2E;1 ?58 75B1;
55;DB? 21719=11 :9;1 1D?= 894B?75 49D5=@1D;1 411= =541
=175D 8?=?75 '5B81D9;1 75B1; 55;DB? 411= =541 =175D
@141 (4)(8 !9;1 C52E18 55;DB? 25B=1CC1 % 25B75B1; 411=
?B29DI1725B:1B9:1B9*45716B5;E5C9=?=5DE=CE4EDI1749=99;9
55;DB? 14118 %.* % 237. C5417;1 1B18 =?=5DE=I1
5525BCE4ED D5B8141@CE=2E05C1BI11BECI17D9=2E1;921D75B1;1
55;DB? 4945699C9;1 C521719 21I1;I1 =E1D1 I17 =5719B D91@
45D9; !149 1BEC I17 49D9=2E;1 75B1;1 55;DB?
)
)
41:E71=5=181=9218G175B1;155;DB?:E71=59=2E;1=541
=175D 971D =541 =175D 49 C5;9D1B 1BEC 9CDB9; 5D9;1 49 D5=@1D
55;DB?21I1;4925B9;1=541=175DI19DE=541=175D41B9E1B
=1;11;1D5B:1499D5B1;C91D1B14E1=175D49D5=@1D99 =@9;1C9I1
14118 41@1D =5=25B9;1 D?BC9 I17 =5I5212;1 75B1;1 55;DB?
25BE218 5C1BI1 D?BC9 1;921D =541 =175D 14118
P M
4571
M
241. %
% *
M
*141571D96=5E:E;;11B18%25B1G1145711B18=?=5DE=CE4ED
!14925C1BI1D?BC9I1749C5212;1?58=541=175D 14118
%
242. C9 M
*?BC9 9918 I17 =5=ED1B ?B29D 55;DB? C589771 25BE218 1B18
'5B81D9;1 (4)(8 I17 =5E;9C;1 ?B29D?B29D 55;DB? 41
@5B81D9;1 @5BE2181 1B18 @ED1B1I1 EDE; =575D18E9 25B1@1
;5=E7;91@5BE218175B1;155;DB?41@1D;9D1981D=51E955B79
=175D9; 41B9 @571BE8 75B1;1 55;DB? 41B9 =541 =175D E1B
5C1B 55B79 =175D =5=5E89 @5BC1=11
3?C 3?C
243. %
L
Gambar 8.17
Gerak elektron dalam medan
magnet B.
L
Gambar 8.18
Arah momentum sudut elektron.
248. M
58 ;1B51 %5 =5=99;9 2525B1@1 919 41 25BC961D 49C;B9D 55B79
9D5B1;C9 =541 =175D9; 99 :E71 =5=99;9 2525B1@1 919
250. %
)521719 3?D?8 :9;1 29171 ;E1DE= 55B79 55;DB? 1;1
=5711=9 @5BE2181 C521719 25B9;ED
5D9;1 %5 55B79 55;DB? =5:149 D?D 55;DB? 1G1
%
M 251. 5D9;1 %5
55B79 55;DB? D5D1@ D941; 25BE218
5D9;1 %5 M 55B79 55;DB? =5:149 D?D 55;DB? 1G1
%
253. 55B79 55;DB? 1;1 @5318 =5:149 21791 C5CE19 4571 919 %
9918 @5D97I1 29171 ;E1DE= =175D9; 411= =55DE;1 75B1;
?B29D 55;DB?
'5318I1 D97;1DD97;1D 55B79 99 D518 491=1D9 ?58 ',,4(5
=51E9 5;C@5B9=5I1 1 =571=1D9 C@5;DBE= 1D?= 894B?75 ;5D9;1
4925B9 =541 =175D9; ;E1D D5BI1D1 71B9C71B9C C@5;DBE= I17 491=1D9
@5318 =5:149 2525B1@1 21791
'5318I171B9CC@5;DBE=99D5BI1D11;921DDB1C9C941B9D97;1D55B79
I17 D5B@5318 9DE 41@1D 41 @181=9 @141 (4)(8 '5BE2181
;53955B79=5=5E89@5BC1=11 C58977141@1D=5=571BE89
@1:1775?=217=51E9=5D?454965B5C91C9
1;149@5B?58
256. elektron dilepas
Na Na
1 2
Gambar 8.20
(a) Atom Na, kulit terluarnya terisi
satu elektron.
(b) Atom Na yang stabil setelah
melepas elektron terluarnya.
Mn Na
1 2
Fisika Atom 217
Contoh 8.8
9DE718@5BE2181@1:1775?=2176?D?I17D5B:1491;921DDB1C9C941B9 277. P
!C
P
= C
3. Sifat Atom
)961DC961D CE1DE ECEB 41@1D 491=1D9 4571 =5981D CDBE;DEB
1D?=I1)ECE155;DB?411=CE1DE1D?=41@1D49@1;19C52171941C1B
EDE; =575D18E9 C961DC961D 1D?= D5BD5DE '141 C521791 ECEB ;E9D
;E9D 1D?= 141 I17 D5B9C9 @5E8 55;DB? 41 141 I17 ;?C?7 E9D
I17 D941; @5E8 D5B9C9 55;DB? 25B141 @141 ;E9D @197 E1B 5;DB?
@141 ;E9D D5BE1B 99 491=1;1 $#,*' .$+!
'579C91 55;DB? 49=E19 41B9 D97;1D 55B79 D5B5418 ?697EB1C9
I17=1D1@D5B41@1D@141CE2;E9DI17D5B9C9@5E8!9;1CE2;E9DD518
D5B9C9 @5E8 C9C1 55;DB? 1;1 =579C9 CE2;E9D C51:EDI1 $9C1I1
141 C1DE 55;DB? I17 D5B9C9 @141 CE2;E9D D5BE1B =1;1 55;DB? 99
3545BE7 =E418 5@1C CE@1I1 1D?= =5:149 CD129 '55@1C1 55;DB?
99 41@1D D5B:149 4571 31B1 25B9;1D1 4571 1D?= 19
)521719 3?D?8 1D?= %1 I17 =5=99;9 ;?697EB1C9
280. + + ( +
E9D D5B49B9 1D1C CE2;E9D + ( 41 1B9 ;?697EB1C9 1D?= %1 @141
(4)(8
D5B981D 81I1 141 C1DE 55;DB? I17 =579C9 ;E9D
I19DE@141?B29D++DE;=5:149CD1291D?=%13545BE7=55@1C;1
C1DE 55;DB? D5BE1BI1 I17 D5B41@1D @141 ;E9D )5219;I1 :9;1
@141 CE2;E9D D5BE1B ;5;EB171 C1DE 55;DB? EDE; =5:149 CD129
1D?= 99 3545BE7 =E418 =55B9=1 C1DE 55;DB? 41B9 E1B
'5B81D9;1:E71(4)(8
'1411D?= 281. $;E9DD5BE1BI1I19DE
;E9D D5B9C9 55;DB? E9D D5B9C9 =1;C9=1 55;DB? 25B1BD9
D5B41@1D ;5;EB171 55;DB? C589771 1D?=$ 3545BE7 =55B9=1
C1DE 55;DB? 41B9 1D?= 19 CE@1I1 =5:149 CD129 D?= %1 41 $
41@1D 25B712E7 =5:149 =?5;E I17 CD129 ;1B51 @141 C5D91@ 1D?=
1;1 =5=99;9 ;E9D 1D1E CE2;E9D I17 D5B9C9 @5E8 ?58 55;DB?
e
Gambar 8.21
(a) Atom Mn menerima elektron
dari atom Na.
(b) Atom Na yang tidak stabil.
282. 1B9 EB191 D5BC52ED 41@1D 491=29 ;5C9=@E1 218G1 1D?=1D?=
3545BE7 EDE; =5=99;9 ;?697EB1C9 C5@5BD9 71C =E91 I19DE =5=99;9
;51411 I17 CD129 4571 31B1 =55@1C 1D1E =55B9=1 55;DB?
4. Sistem Periodik
)9CD5= @5B9?49; ECEBECEB 49CECE 25B41C1B;1 ;519;1 ?=?B
1D?= 1D1E 25B41C1B;1 :E=18 55;DB? )9CD5= @5B9?49; 25BDE:E1
=5:51C;1C961DECEBECEB@141@5B9?49;417??71D5BD5DEC5BD1
=5:51C;1=571@1ECEBECEB411=C1DE@5B9?45=5=99;9C961DI17
25B2541 1D1B1 7??71 I17 C1DE 41 7??71 I17 19I1
+CEBECEB 7??71 1;19 41 1;19 D118 ;54E1I1 D5B=1CE;
7??71 + ;1B51 411= ;?697EB1C9 55;DB? 491;89B9 4571 CE2;E9D +
!1B9:1B91D?=49C52518;9B9B51D96529825C1B4921497;14571ECEB
ECEB C52518 ;11I1 41I1 55;DB? D5BE1B 99 =5=25B9;1 C961D
;?4E;D?B 9CDB9; I17 219; 5B51;D961I1 3E;E@ D9779 EDE; 25B51;C9
4571ECEB19D5BED1=14571ECEB7??7181?75;1B51I17
C1DE =E418 =55@1C;1 55;DB? 41 I17 19 =5=99;9 ;53545BE71
25C1B EDE; =55B9=1 55;DB?
+CEBECEB7??71(I17D941;D5B9C9@5E8?5855;DB?411=
;?697EB1C9I1 D5B981D ;5;EB171 55;DB? EDE; =5=99;9 ;?697EB1C9
C5@5BD9 71C =E91 !9;1 41 @5B81D9;1 7??71 81?75 ECEBECEB
99 3545BE7 =E418 =517;1@ 55;DB? EDE; =5=25DE; C5I1G1
9;1D1;1 ECEBECEB D5BC52ED =5=99;9 ;5B51;D961 I17 D9779
4921497;1 4571 ECEB 7??71 ( 19I1
??7171C=E91=5=99;9;?697EB1C955;DB?I17CE418@5E8
@141 ;E9D D5BE1BI1 53545BE71 =517;1@ 1D1E =55B9=1
55;DB? C171D ;539 1 99 =5I5212;1 ECEB 71C =E91 D941;
=5=25DE; C5I1G1 4571 ECEB 19
'B9C9@ '1E9 1DEB1 E621E 41 ;19418 E4 C171D =5=21DE
EDE; =5=181=9 ;5D5B1DEB1 CECE1 55;DB? 1D1E CE2;E9D 411=
416D1B 25B;11 ?697EB1C9 55;DB? 411= 1D?= 14118 CECE1
55;DB? 411= 1D?= C5CE19 4571 D97;1D 55B79I1 11=
@5=2181C1 99 1;1 41 D9:1E ;?697EB1C9 55;DB? @5B CE2;E9D
571;?697EB1C955;DB?D5BC52ED41@1D49;5D18E929171;E1DE=
I17 25B;19D1 41 C961DC961DI1 41@1D 49;5D18E9 41B9 :E=18 55;DB?
D5BE1B DEB1 @5E9C1 ;?697EB1C9 55;DB? 25B41C1B;1 8181
25B9;ED 99
a. Aturan Aufbau
$5EBED 1DEB1 E621E 55;DB? 411= CE1DE 1D?= 1;1 =E19
=579C9 CE1DE ?B29D1 41B9 D97;1D I17 55B79I1 @197 B5418 C1=@19
I17@197D9779*91@D97;1D155B79499C955;DB?C521I1;=E7;9
C1=@19@5E8*91@;19;51411 @5E8;5141125B9;EDI1=E19
499C945=9;91C5D5BECI1'B9C9@@579C919941@1D4971=21B;1411=
25DE; 4917B1= @141 (4)(8
'5B81D9;1 8E2E71 29171 ;E1DE= ED1=1 41 29171
;E1DE= ?B29D1 1D1E 1J9=ED C521719 25B9;ED +BED1 D97;1D 55B79
C5CE19 4571 EBED1 1B18 @118 I19DE
+ 285. 55;DB?( 55;DB?
55;DB? 55;DB?
Tantangan
untuk Anda
Jelaskan sifat-sifat yang dimiliki atom
berikut ini.
1. 40
20Ca
2. 30
31Ga
3. 80
35 Br
4f
Gambar 8.22
2p
3p
4p
5p
6p
3d
4d
5d
6d
Pengisian elektron menurut
aturan Aufbau.
1s
2s
3s
4s
5s
6s
7s
218 Mudah dan Aktif Belajar Fisika untuk Kelas XII
286. Fisika Atom 219
)521719 3?D?8 @5B81D9;1 31B1 @5E9C1 ;?697EB1C9 55;DB?
25B9;ED
D?==5=99;9?=?B1D?=25B1BD9411=@141C5D91@1D?=I1
D5B41@1D 51= 55;DB? C589771 ;?697EB1C9I1 + 289. D?= =5=99;9 ?=?B 1D?= 25B1BD9 @141 C5D91@ 1D?=I1
D5B41@1D 55;DB? C589771 ;?697EB1C9 55;DB?I1 + 293. (+
D?= ? =5=99;9 ?=?B 1D?= 301. 1B1 @5E9C1 D5BC52ED 3E;E@ @1:17 C589771 81BEC 491;E;1
@5I97;1D1 25B41C1B;1 ;?697EB1C9 71C =E91 I19DE
312. (
571 45=9;91 ;?697EB1C9 55;DB? @141 3?D?8 D5BC52ED
49C97;1D C521719 25B9;ED
+
327. c. Aturan Hund
$5EBED;5+411=?B29D1I17C5D97;1D55;DB?55;DB?D941;
2?58 25B@1C171 C525E= C5EBE8 ?B29D1 C5D97;1D D5B9C9 ?58 C52E18
55;DB? '55=@1D1 55;DB? @141 ?B29D1 ( I17 =5=99;9 D97;1D
55B79 I17 C1=1 @141 CE2;E9D I17 C1=1 =1C97=1C97 499C9 4571
C1DE55;DB?D5B5298418EE45711B18C@9I17C1=121BE;5=E491
499C9 4571 55;DB? 25B9;EDI1 4571 1B18 I17 25B1G11
1 99 25B1BD9 C5=E1 55;DB? 25B=E1D1 C1=1 C589771 55;DB?
1;1 =55=@1D9 ?B29D1 I17 =1C98 ;?C?7 C525E= 25B@1C171
$9C1;1 1D?= 4571 ?=?B 1D?= 41 ;?697EB1C9 55;DB?I1
+ 330. 4917B1= ;?697EB1C9 55;DB?I1 14118
2E;1
c. Asas Larangan Pauli
$5EBED63-.(5.!(;30411=CE1DE1D?=D941;2?5814155;DB?
I17=5=99;9;55=@1D29171?B29D141=175D9;I17C1=19171
;E1DE= C@9I1 81BEC 25B1G11 % 41 %C
2E;1
C1C 99 C171D @5D97 EDE; =5=181=9 CDBE;DEB 1D?= 1@1179 EDE;
=57;1:9 C961DC961D 1D?= 25B55;DB? 21I1;
)5;1B17 D9:1E 859E= 4571 ?=?B 1D?= 332. 5;DB? ;54E1 29C1 =5=99;9
;5D971 29171 ;E1DE= 41 % C1=1 D5D1@9 29171 ;E1DE=
;55=@1D %C 81BEC 25B2541 58 ;1B51 55;DB? @5BD1=1 %C
334. Gambar 8.24
Proses untuk menghasilkan
spektrum emisi
C1C 1B171 '1E9 :E71 =5=21D1C9 C5D91@ ?B29D1 81I1 =1=@E
=51=@E7=1;C9=E= 335. 55;DB?41411=C1DE?B29D181BEC=5=99;9
C@945711B1825B1G11@1291411=?B29D114155;DB?;5D971
=9C1I1 C@9 C51B18 4571 C@9 55;DB? @5BD1=1 (4)(8
;E=@E1 ;55=@1D 29171 ;E1DE= 55;DB? ;5D971 @5BC9C C1=1
4571 55;DB? @5BD1=1 9 :51C =517771B 1C1C 1B171 '1E9
5. Spektrum Emisi dan Spektrum Absorpsi
01D @141D =1E@E J1D 319B @141 CE8E D5BD5DE 41@1D =5=131B;1
B1491C94571@1:1775?=217I1725B25412541@141D97;1D55B79
I17 25B2541 1B9 25B21719 C579 I17 41@1D 491=1D9 B1491C9 99 41@1D
49D5B17;1?5841C1BD5?B9;E1DE=3181I141D941;25B71DE7@141
@5B9391 @B?C5C B1491C9 9DE C549B9 1D1E 41B9 C961D =1D5B91I1 *97;1D
55B79I1 25B71DE7 @141 29171 ;E1DE=I1 5B41C1B;1 81C9
@55=E1 99 41@1D 49C9=@E;1 218G1 I17 D5B:149 14118 ;51;E1
;?5;D96 C5:E=18 1D?= I17 C197 25B9D5B1;C9 41B9 ;1B1;D5B9CD9; 1D?=
1D?= 41B9 ECEBECEB D5BD5DE
a. Spektrum Emisi
'141 ;?49C9 D5BD5DE 1D?= 1D1E =?5;E @141 71C 25BD5;11 B5418
25B:1B1; B1D1B1D1 3E;E@ :1E8 C589771 9D5B1;C9 I17 D5B:149 81I1 C11D
25BDE=2E;1 11= ;51411 C5@5BD9 99 4981B1@;1 218G1 B1491C9 I17
49@131B;1=5BE@1;1;1B1;D5B9C9D9;41B91D?=1D1E=?5;EC531B1949F94E
I17D5B41@1D49C11199D5B2E;D9C531B15;C@5B9=5D1!9;171C1D?=9;
1D1E E1@ 1D?=9; I17 25BD5;11 49 21G18 D5;11 1D=?C65B 495;C9D1C9;1
291C1I14571=5719B;11BEC9CDB9;B1491C9I1749@131B;1=5=99;9
C@5;DBE= I17 25B9C9 @1:17 75?=217 D5BD5DE C1:1
)@5;DBE= 5=9C9 14118 C@5;DBE= I17 4981C9;1 ?58 @131B1
75?=217 55;DB?=175D9; =9C1I1 3181I1$1D181B9 I17 4981C9;1 ?58
1D?=1D?= 71C CE1DE ECEB !9;1 3181I1 D12E7 71C ECEB 495G1D;1 @141
C52E18 @B9C=1 3181I1 1;1 D5BEB19 =5:149 2525B1@1 71B9C G1B1 C@5;DBE=
I17 C5D91@ C@5;DBE= =5=99;9 @1:17 75?=217 I17 25B2541
+DE; =57EB19;1 3181I1 71C CE1DE ECEB 41@1D 497E1;1 ;9C9
25BE@1 71B9C71B9C @5=9C18 I17 C171D B1@1D '5B11D1 EDE; =57
81C9;1 C@5;DBE= 5=9C9 41@1D 49981D @141 (4)(8
336. $9C1I1 3181I1 I17 49@131B;1 9DE 4981C9;1 ?58 1D?=1D?=
71C 894B?75 5;DB? @141 1D?= 71C 1;1 D5B5;C9D1C9 ;5 D97;1D 55B79
I17 5298 D9779 :9;1 =541@1D D1=2181 55B79 41B9 E1B $9C1I1
41B9 + ;5 338. ( 5D9;1 55;DB? ;5=219 ;5 D97;1D 55B79 41C1B
1D?= 1;1 =5=131B;1 55B79 25BE@1 75?=217 55;DB?=175D9;
5?=217 55;DB?=175D9; 99 =55G1D9 3518 C5=@9D ;5=E491 ?58
;9C9 1;1 49EB19;1 =5:149 2525B1@1 G1B1 )5D518 ;5E1B 41B9 ;9C9
@141 1I1B 1;1 D1=@1; 71B9C71B9C 25BG1B1 I17 C5D91@ G1B1 C5CE19
4571 55B79 D5BD5DE
*941; C5=E1 G1B1 C@5;DBE= 1;1 =E3E @141 C5D91@ C@5;DBE=
CE1DE ECEB D5D1@9 81I1 G1B1G1B1 D5BD5DE C1:1 I17 1;1 =E3E
+DE; C5D91@ ECEB 1;1 =5=131B;1 C@5;DBE= I17 25B191 1
9918 I17 =5=2541;1 ECEB I17 C1DE 41 ECEB I17 19
220 Mudah dan Aktif Belajar Fisika untuk Kelas XII
benar salah
Gambar 8.23
Berdasarkan asas larangan Pauli,
satu orbital maksimum ditempati
dua elektron dengan spin yang
berlawanan.
sumber celah
kisi
spektrum
339. Fisika Atom 221
5B41C1B;1@5BC1=11@1:1775?=217I17CE41841;51
6B5;E5C9C5214974571,,(/*(E=EC1@1:1775?=217
41@1D 49DE9C;1
342. M
5D5B171
D5D1@1(I425B7
P
=
@1:17 75?=217 55;DB?=175D9; =
29171 ;E1DE= ED1=1
)@5;DBE= 5=9C9 141 D971 =131= I19DE +(#,*-% *!+ +(#,*-% (!,
41 +(#,*-% #',!-
#7,2:8;4 (809
)@5;DBE= 71B9C 4981C9;1 ?58 71C71C 25BD5;11 B5418 I17
49@11C;1 )@5;DBE= 99 D5B49B9 1D1C 71B9C71B9C 3181I1 =??;B?=1D9;
4571 @1:17 75?=217 D5BD5DE '1:17 75?=217 3181I1 I17
D5B41@1D 411= C@5;DBE= =5BE@1;1 ;1B1;D5B9CD9; 41B9 ECEB I17
=5781C9;1 C@5;DBE= D5BC52ED ;921D @5=11C1 1D?= 71C 1;1
=5I5B1@ 55B79 C589771 25B141 411= ;51411 D5B5;C9D1C9 11=
;51411 99 1D?= 71C D941; CD129 41 1;1 25BEC181 ;5 ;51411 41C1B
4571 =5=131B;1 6?D? 25BE@1 75?=217 55;DB?=175D9;
#7,2:8;4 !0:(
)@5;DBE=@9D14981C9;1?5871C411=;51411=?5;E5B=9C1I1
71C 344. 41 )@5;DBE= I17 4981C9;1 25BE@1 ;5?=@?;
71B9C71B9C I17 C171D B1@1D C589771 =5=25DE; @9D1@9D1
#7,2:8;4 65:05;
)@5;DBE= ;?D9E 14118 C@5;DBE= I17 D5B49B9 1D1C 3181I1 4571
C5=E1 @1:17 75?=217 G11E@E 4571 9D5C9D1C I17 25B2541
)@5;DBE= ;?D9E 4981C9;1 ?58 J1D @141D J1D 319B 41 71C I17
25BD5;11D97794125B@9:1B5B@9:1BI125DE;J1DJ1DD5BC52ED;1B51
=5=99;9 1D?= I17 25B:1B1; B51D96 5298 ;539 C1DE 41 I17 19I1
C589771 C197 25B9D5B1;C9 ;921DI1 D97;1DD97;1D 55B79 1D?=
25B75C5B EDE; =5=5E89 1DEB1 '1E9
b. Spektrum Absorpsi
)@5;DBE= 12C?B@C9 14118 C@5;DBE= I17 D5B:149 ;1B51 @5I5B1@1
@1:17 75?=217 D5BD5DE 41B9 CE1DE 3181I1 )@5;DBE= 12C?B@C9 D5B49B9
1D1C C545B5D1 71B9C 89D1= @141 C@5;DBE= ;?D9E '5I5B1@1 D5B8141@
@1:1775?=217D5BD5DED5B:149@1416?D?I17=5=99;955B79I17
D5@1D C1=1 41 C59C98 55B79 1D1B1 D97;1D 5;C9D1C9 41 D97;1D 41C1B
)@5;DBE= 12C?B@C9 4981C9;1 :9;1 3181I1 @ED98 495G1D;1 @141
D12E7I1725B9C91D?=1D?=71CCE1DEECEBI17;5=E4911D?=1D?=
D5BC52ED 1;1 =5I5B1@ =5712C?B@C9 C521791 3181I1 @ED98 1B9C
71B9C I17 4981C9;1 C5CE19 4571 71B9C71B9C @141 C@5;DBE= 5=9C9 !9;1
;54E1C@5;DBE=994945;1D;11;1D1=@1;71B9C71B9C751@41D5B17
?D?8 C@5;DBE= 12C?B@C9 14118 C@5;DBE= $1D181B9 )531B1
C5@9D1C C@5;DBE= $1D181B9 D1=@1; C5@5BD9 C@5;DBE= ;?D9E ;1
D5D1@9:9;14935B=1D91;1D1=@1;71B9C71B9C751@D5B17I1749C52ED
*!+*!+*- '*41I1*!+*!+*- '*49C5212;13181I1
@ED98 41B9 21791 9D9 $1D181B9 49C5B1@ ?58 1D?=1D?= 41 =?5;E
=?5;E 71C 411= 1D=?C65B $1D181B9 =1E@E 1D=?C65B E=9 1791
$1D181B9I1725BCE8EC5;9D1B
?41@1D=59=2E;1C@5;DBE=
345. cahaya
putih celah
kisi
spektrum
energi ionisasi semakin besar
222 Mudah dan Aktif Belajar Fisika untuk Kelas XII
energi ionisasi semakin besar
(4)(8
=5=@5B981D;1 2171 41 @5B11D1 C@5;DBE=
12C?B@C9 5B41C1B;1 81C9 @5B3?211 41 81C9 5;C@5B9=5 49@5B?58
;5C9=@E1218G1:9;1J1D25B@541B25B1491C9 =5=131B;1C@5;DBE=
5=9C9 =5BE@1;1 J1D I17 219; EDE; =5712C?B@C9 C@5;DBE=I1
1B9CC@5;DBE=1D?=894B?75D5B49B91D1C2525B1@145B5DI19DE45B5D
#I=1 45B5D 1=5B 45B5D '1C385 45B5D B13;5DD 41 45B5D '6E4
5B5D45B5D D5BC52ED =5=5E89 @5BC1=11
0
348. M
5D5B171
0?=?B1D?=
6. Energi Ionisasi, Afinitas Elektron, dan Elektron Valensi
)E1DE 1D?= 1;1 25B9;1D1 4571 1D?= 19 ;1B51 141I1 61;D?B
61;D?B D5BD5DE 5=1=@E1 CE1DE 1D?= EDE; 25B9;1D1 4571 1D?=
19 49D5DE;1 ?58 ;51411 :E=18 55;DB? D5BE1BI1 5;DB?
=5=99;9;53545BE71EDE;=5=25DE;CECE1I17CD129CECE1
71C =E91 525B1@1 61;D?B I17 =5=571BE89 1D?= EDE; =55@1C;1
1D1E =579;1D 55;DB? 14118 C521719 25B9;ED
a. Energi Ionisasi
!9;1CE1DE1D?=D5B41@1DC1DE55;DB?49E1BCE2;E9DI17=1D1@
55;DB? 3545BE7 =E418 =55@1C;1 9;1D1I1 171B =5=99;9
;?697EB1C9 C5@5BD9 71C =E91 +DE; =55@1C;1 55;DB? D5BE1BI1 99
49@5BE;1 55B79 I17 49C52ED *! !'!++! 5B79 9?9C1C9 EDE; 1D?=
894B?75 C525C1B
5,
'57E;EB1 55B79 9?9C1C9 @141 ECEB 411= 71C =5=@5B981D;1
218G1 411= CE1DE @5B9?45 C5=1;9 21I1; 55;DB? 41 @B?D? =1;1
71I1 D1B9;=51B9; 55;DB? D5BE1B 4571 9D9 C5=1;9 25C1B :1B9:1B9
;539 ;921DI1 55;DB? CE;1B 495@1C C589771 55B79 EDE; =55@1C
55;DB? C5=1;9 25C1B I17 25B1BD9 55B79 9?9C1C9 25C1B
!9;1 :E=18 55;DB? C549;9D C5@5BD9 ECEB @141 7??71 :1B9
:1B9I1 25C1B 71I1 D1B9; =51B9; 55;DB? 4571 9D9 5298 ;539
;921DI1 55B79 EDE; =55@1C 55;DB?
D5BE1B B51D96 5298 ;539 I17 25B1BD9 55B79
9?9C1C9I1 ;539 1B9 1D1C ;5 21G18 411=
C1DE 7??71 :1B9:1B9 1D?= C5=1;9 25C1B
199=5I5212;155;DB?D5BE1BB51D96
=E418 5@1C 4921497;1 4571 1D?=
I17 25B141 49 1D1CI1 1 99 25B1BD9 41B9
1D1C ;5 21G18 411= C1DE 7??71 55B79
9?9C1C925B;EB17'5BE218155B799?9C1C9
411= D125 @5B9?49; 41@1D 49981D @141
(4)(8
??71 411= CECE1 25B;11
ECEBECEB C5@5BD9 71=21B 49C52ED :E71
7??711;19I17=59@ED9#9%1(2
C41B+CEBI17@197C549;9D14118
6B1C9E= B C5212 25BC961D B149?1;D96 C589771 =E418 25BE218 =5:149
ECEB 19
Gambar 8.25
Proses untuk menghasilkan
spektrum absorpsi
atom-atom
gas
Gambar 8.26
Perulangan sifat pada sistem
periodik
