vat li hat nhan_li thuyet va bai tap

8/6/2019 Vat Li Hat Nhan_li Thuyet Va Bai Tap

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S LC V HT NHN NGUYN T

I. TM TT L THUYT

1. Cu trc ht nhn. ht khi v nng lng lin ktHt nhn nguyn t bao gm cc proton v notron gi chung l cc ht nuclon. Cc nuclon nylin kt bng lc ht nhn, l loi lc c c li tng tc rt nh. Mt ht nhn X c Z proton v Nnotron th s c Z = A + N nuclon, s c k hiu l . Z cng chnh l v tr ca nguyn ttng ng trong bng h thng tun hon.

Khi lng ca cc nuclon hay cc ht nhn c o bng n v Cacbon, l khi lng bng1/12 khi lng ca ht nhn C12, k hiu l u . Khi lng ca proton l 1,0073 u, khi lngca notron l 1,0087 u.n v khi lng u cng c th vit l 931 MeV/c2.

iu c bit l tng khi lng m0ca cc nuclon cu thnh baogi cng ln hn khi lng mca ht nhn. Gi m = m0 m l ht khi ca ht nhn. Theo h thc nng lng caAnhxtanh, ta thy nng lng gii phng cc nuclon trong ht nhn thnh cc nuclon ring rti thiu phi l m.c2. Nng lng gi l nng lng lin ktca ht nhn.

2. Phng x.S phng x l ht nhn pht ra cc tia phng x v bin i thnh ht nhn khc. Cc tia phngx c th l tia gm cc ht nhn ht Heli, tia gm cc electron hoc phn electron h ay cc tiagamma l cc sng in t mnh.

Bn cht ca phng x +l mt proton bin thnh mt notron v mt ht e+:

p n + e+

Bn cht ca phng x -l mt notron bin thnh mt proton v mt ht e-:

n p + e-.

S phng x khng ph thuc vo cc iu kin bn ngoi nh p sut, nhit , nh sng. C saumt khong thi gian T gi l chu k bn r th s lng ht nhn phng x gim i mt na. Dod ta vit:

N = N0.

Hoc N = N0.e-tvi = ln2/T

T ta cng c:

m = m0.e-t = m0. .

n = n0.e-t = n0. .

phng x hay hot phng x l s ht phng x trong mt giy. Mt phng x trn giy gil mt Bec-c-ren (Bq), 1 Curi (Ci) l 3,7.1010phng x trn giy: 1 Ci = 3,7.1010 Bq.


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Ta cng c:

H = H0.e-t

= H0. .

3. Phn ng ht nhnPhn ng ht nhn l tng tc ca cc ht nhn dn n s to thnh cc ht nhn khc.

Trong phn ng ht nhn, khi lng c th thay i nhng cc i lng sau y c bo ton:

Tng s khi ca cc ht nhnTng in tch ca cc ht nhnNng lng ca cc ht nhnng lng ca cc ht nhn.

4. Phn ng phn hch v phn ng nhit hch Phn ng phn hch l s hp th notron ca mt ht nhn s khi ln ri v thnh hai ht nhntrung bnh. Phn ng ny thng km theo s phng ra cc notron khc.

Ty theo h s nhn notron (s notron pht ra trong mi phn ng) v kt cu ca mu cht mphn ng c duy tr hay khng.

Phn ng nhit hch l s kt hp gia cc ht nhn nh di tc dng ca nhit cao thnh ccht nhn ln hn. Nhit cho phn ng ny xy ra l hng triu . Do , phn ng nhithch xy ra, trc cn c mt phn ng phn hch

II. TM TT CNG THC

Ni dung Cc cng thc Ghi ch

Cu trc ht nhn. ht khi, nng lnglin kt

n =

N = n.NA.

m = Zmp + Nmnm = Zmp

+ (A - Z)mnm

Elk= m.c2

Phng x. nh lutphng x

m = m0.e-t = m0.

n = n0.e-t = n0.

H = - = -N = N

H = H0.e-t = H0.


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Phn ng ht nhn. Ccnh lut bo ton

Qta = (m1m2)c2

Qthu = (m2m1)c2

K2 = K1 + Qta = K1 - QthuP = mv, p2 = 2mK

III. DNG BI C BN

Bi 1: Cu trc ht nhn. Nng lng lin kt

Phng php gii:S proton trong ht nhn: ZS nuclon: AS notron: A - Z ht khi: m = Zmp + Nmnm = Zmp + (A - Z)mn - mNng lng lin kt: Elk= m.c

2.

V d 1: Ht nhn Natri c k hiu v kh lng ca n l mNa = 22,983734 u, bit mp =1,0073 u, mn = 1,0087 u.

a. Tnh s ht notron c trong ht nhn Na.b. Tnh s nuclon c trong 11,5 g Na.c. Tnh ht khi v nng lng lin kt, nng lng lin kt ringca ht nhn Na.

Li gii:

a. S notron ca Na: N* = 23 11 = 12.b. S mol Na c trong 11,5 g Na: n = = 0,5.

S nguyn t cha trong : N = n.NA = 0,5.6,02.1023 = 3,01.1023.

Mi nguyn t Na c 23 nuclon, vy trong tng nguyn t th s nuclon l:N

1= N.23 = 69,23.10

23.

c. ht khi: m = 11. 1,0073 + 13. 1,0087 - 22,9837 = 0,201 (u)Nng lng lin kt ca Na: E lk= 0,201.931 = 187 (MeV).


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Bi 2: Phng x. Hot phng x

Phng php gii:

Hot phng x hay phng x: H = - = -N = N.

Khi lng ca cht phng x ph thuc t theo cng thc: m = m0.e-t = m0. .

S mol ca cht phng x ph thuc t theo cng thc: n = n0.e-t = n0. .

phng x ca cht phng x ph thuc t theo cng thc: H = H0.e-t = H0. .

V d 2: Urani 23892U c chu k bn r l 4,5.109nm.a. Gi s rng tui ca Tri t l 5 t nm. Hy tnh lng cn li ca 1 g U238 k t

khi Tri t hnh thnh.b. Tnh phng x ca mt mol U238 v phng x ca lng cn li sau thi gian

2,25 t nm.

Li gii:

a. Khi lng cht phng x c tnh theo cng thc:m = m0. .

Thay s m0 = 1g, t = 5.109, T = 4,5.109ta tnh c m = 0,463 g.b. phng x c tnh theo cng thc: H = N

Trong = ln2/T vi T tnh ra giy.= ln2/(4,5.109.365.86400)N = nNA = 6,02.10

23.

Thay s ta tnh c H = 2,94.106

Bq. phng x ph thucthi gian theo cng thc: H = H0.e

-t = H0. .

Vi t = 2,25.109nm th H = 2,94.106. = 2,1.106 (Bq).

Bi 3: Tm chu k phng x. Tm tui ca c vt

Phng php gii:S dng cc cng thc v s phng x nh dng 3 nu trn.

Xt cng thc: m = m0. .

= -log2 Ta c th tnh t hoc T.Abc

V d 3: Khi phn tch mt mu g, ngi ta thy 87,5% s nguyn t ng v phng x 146C bphn r thnh cc nguyn t 177N . Bit chu k bn r ca

14

6 C l 5570 nm. Tui ca mu

g ny l bao nhiu?


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Li gii: Khi 87,5% s nguyn tb phng x th s nguyn t cn li ch l 22,5 % tc l:

N = 0,225N0.

M N = N0. => = 0,225 = - log20,225 = 2,15 t = 2,15T.

Thay s ta tnh c 11976 (nm).

Bi 4: Cht phng x v cht to thnh

Phng php gii:Lu rng c bao nhiu ht phng x th c by nhiu ht to thnh. S ht phng x(chnh l s ht to thnh) c tnh:

Nu thi gian so snh c vi chu k: N = N0N = N0(1 - ).Nu thi gian rt nh so vi chu k: N = H.t= N.t

T s s ht cht cn li trn s ht cht to thnh: = ( )/(1 - ).

T s khi lng cht cn li trn khi lng cht to thnh: = . .

V d 4: Urani 23892U c chu k bn r l 4,5.109nm. Khi phng x , urani bin thnh Thri234

90Th . Ban u c 23,8 g urani.

a. Tnh s ht v khi lng Thori sau 9.109nm.b.

Tnh t s s ht v t s khi lng sau 4,5,10

9

nm.

Li gii: Phng trnh phng x: +

Ta thy mt nguyn t U phng x cho mt nguyn t Th

Trong 23,8 g U ban u tng ng 1 mol th c 6,02.1022nguyn t U.

a. Sau thi gian 9.109nm tng ng 2 chu k, s lng ht U s gim i 4 ln, tc lcn li , hay s ht phng x l . Vy s ht U phng x hay s ht Th to thnhl:

NTh = .6,02.1022

= 4,515.1022

.

Ta cng thy rng khi lng U phng x hay 17,85 g U phng x. C 238 gU phng x th to thnh 234 g Th. Vy khi lng Th to thnh l:

mTh = 17,85. = 17,55 (g).

b. Cn c lp lun trn, ta thy t s gia s ht v ht l 1/3.Khi lng U cn li l: .23,8 = 5,95.T s gia khi lng v l: 5,95:17,55 = 0,339 1/2,95.

Ta thy rng t s khi lng khc t s s ht ca cc cht urani v thori.


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Bi 5: Bi ton hai cht phng x vi chu k bn r khc nhau

Phng php gii:Vit biu thc s ht hoc khi lng cn li ca cc cht phng xThit lp t s ca s ht hoc khi lng cc cht phng x

V d 5: Cho bit 23892U v 23592U l cc cht phng x c chu k bn r ln lt l T1 = 4,5.109nmv T2=7,13.10

8nm. Hin nay trong qung urani thin nhin c ln U238 v U 235 theo

t l 160 : 1. Gi thit thi im to thnh Tri t t l 1:1. Cho ln10 = 2,3; ln2 =0,693. Tui ca Tri t l bao nhiu?

Li gii: Gi N0l s ht ban u (khi Tri t hnh thnh) ca U238 v U235.

S ht U238 hin nay l: N1 = N0.

S ht U235 hin nay l: N2 = N0.

=Ta thy chu k bn r ca U235 nh hn, tc l U235 phng x nhanh hn, suy ra rng sht cn li ca n phi t hn.

Kt hpgi thit ta c = 160.

= 160 t( ) =log2160

t( ) = log216 +

t( ) = 7,32

t = 7,32.

t= 6,2.109(nm)

Theo tnh ton trn, tui ca Tri t l 6,2 t nm.


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Bi 6: Tnh nng lng ta ra hay thu vo trong phn ng ht nhn. iukin phn ng

Phng php gii:Gi m1, m2l khi lng trc v sau phn ng.

Nu m1 > m2th phn ng ta mt lng nng lng Q = (m1 - m2)c2.Nu m2 > m1th phn ng thu mt lng nng lng Q = (m2m1)c

2.

iu kin phn ng xy ra l phi nhn nng lng cn thu vo. Nnglng c th l ng nng ca cc ht n.

V d 6: Xt phn ng ht nhn xy ra khi dng ht bn ph nhn Al: 27 3013 15 Al P n. Bitkhi lng ht nhn: mAl = 26,974 u; m = 4,0015 u; mp = 29,97 u; mn = 1,0087 u. ngnngti thiu ca ht phn ng xy ra l bao nhiu?

Li gii: Xt phng trnh phn ng:27 30

13 15 Al P n

Khi lng trc phn ng: m1 = mAl + m = 26,974 + 4,0016 = 30,9756 (u)

Khi lng sau phn ng: m2 = mAl + m = 29,79 + 1,0087 = 30,9787 (u)

Vy phn ng trn l phn ng thu nng lng.

W1 - W2 = (m2m1)c2 = (30,9787 - 30,9756).931 = 2,89 (MeV).

Sau phn ng, cc ht sinh ra c ng nng. Trng hp ti thiu cc ht sinh ra c ngnng bng 0, tc l W2= 0. Khi ng nng ca cc ht ban u, hay ht l 2,88MeV.

V d 7: Cho phn ng ht nhn: + p + . Bit khi lng ht nhn mNa =22,983734u, mHe = 4,001151u, mp = 1,007276u, mNe = 19,986950u. Phn ng ny tahay thu bao nhiu nng lng.

Li gii:

Khi lng trc phn ng: m1 = mNa + mp = 22,983734 + 1,007276 = 23,99101 (u)

Khi lng sau phn ng: m2 = mHe + mNe = 4,001151 + 19,986950 = 23,988101 (u)

Phn ng ny ta ra mt nhit lng l: Q = (m1m2)c2 = (23,99101 - 23,988101).931 =

2,7 (MeV).


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Bi 7: Vn dng cc nh lut bo ton trong phn ng ht nhn

Phng php gii:Bo ton s khi(s nuclon)Bo ton in tch

Bo ton nng lngBo ton ng lngCh : ng lng l mt vc t.

V d 8: Phn ng phn r uran c dng 238 20692 82

U Pb x y . Tnh x v y trong phng

trnh trn.

Li gii:

Theo nh lut bo ton s khi ta c: 238 = 206 + 4x

Theo nh lut bo ton in tch ta c: 92 = 82 + 2x y

T suy ra x = 8; y = 6.

V d 9: ng v phng x plni 21084 Po l cht phng x to thnh ht nhn X. Cho2

Po Xm 209,9828u;m 4,0015u;m 205,9744u;1u 931MeV / c . Gi s ban u ht

plni ng yn, ng nng ca ht l bao nhiu?

Li gii: Ta c phng trnh phng x nh sau:

+

Khi lng trc phn ng l m1 = 209,9828 u.

Khi lng sau phn ng l m2 = 209,9759 u.

Vy phn ng ta nhit. Nhit lng ta ra l Q = (m1 - m2)c2, hay Q = (209,9828 -

209,9759).931 = 6,42 (MeV).

ng nng sau phn ng bng ng nng trc phn ng cng vi nhit ta ra. Theo githit, ng nng ca Po ban u bng 0, vy tng ng nng caht X v sinh ra bng6,42 MeV.

KX + K = 6,42 (*)

Mt khc theo nh lut bo ton ng lng ta c:

Po = X + .

T gi thit suy ra X + = 0

pX = p


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= (1)Tabit rng biu thc ca ng lng: p = mv, cn biu thc ng nng: K = mv 2/2, suyra

p2

= 2mK

Vy (*) c th vit li:

=

Vi biu thc trn, ta c th ly gn ng m 4, mX 206

K = 51,5KX (**)Gii h gm (*) v (**) ta tnh c K = 6,3 MeV.

V d 10:Bn ht nhn c ng nng 18 MeV vo ht nhn 147 N ng yn ta c phn ng14 17

7 8N O p . Bit cc ht nhn sinh ra cng vc t vn tc. Cho m = 4,0015u;

m p = 1,0072u; m N = 13,9992u; m O =16,9947u; cho u = 931 MeV/c2. ng nng ca ht

prtn sinh ra c gi tr l bao nhiu?

Li gii:

Phng trnh phn ng ht nhn: + +

Khi lng trc phn ng: m1 = m + mN = 4,0015 + 13,9992 = 18,0007 (u)

Khi lng sau phn ng: m2 = mO + mp = 16,9947 + 1,0072 = 18,0019 (u).

Nh vy phn ng thu nng lng.

Nng lng thu vo: Q = (m2m1)c2

hay Q = (18,0019 - 18,0007).931 = 1,12 (MeV)

ng nng cc ht sau phn ng: KO + K = 181,12 = 16,88 MeV (*)

Cc ht O v c cng vn tc nn t s ng nng ca chng bng t s khi lng. Cth ly gn ng khi lng bng s khi (vi n v u), ta c:

= = 4,25

Thay vo h thc (*) ta tnh c K = 3,26 MeV v KO = 13,66 MeV.

Ch : Chng ta c hai bi ton phn ng ht nhn ph bin l bi ton mt ht ng yn v thnhhai ht v bi ton mt ht bay vo va chm vi mt ht ng yn sinh ra hai ht.

IV. BI TP N LUYN

Bi t lun:


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9.1.Ht nhn heli c 4,0015u. Tnh nng lng lin kt v nng lng lin kt ring ca ht nhn hli.Tnh nng lng ta ra khi tao thnh 1g hli. Cho bit khi lng ca prton v ntron l mp =1,007276u v mn = 1,008665u; 1u = 931,5MeV/c

2v s avgar l NA = 6,022.1023mol-1.

9.2.Tnh nng lng lin kt ring ca hai ht nhn He2311 v Fe56

26 . Ht nhn no bn vng hn ? Cho

mNa = 22,983734u ; mFe = 55,9207u mn = 1,008665u ; mp = 1,007276u.

9.3.Plni Po210

84 l nguyn t phng x , c chu k bn r 138 ngy, n phng ra 1 ht v bin i

thnh ht nhn con X.a. Vit phng trnh phn ng. Nu cu to, tn gi ca ht nhn X.b.Mt mu plni nguyn cht c khi lng ban u 0,01g. Tnh phng x ca mu cht trn

sau 3 chu k bn r.

9.4.Ht nhn C146 l mt cht phng x, n phng x ra tia-c chu k bn r l 5730 nm.

a. Vit phng trnh ca phn ng phn r.b.Sau bao lu lng cht phng x ca mt mu ch cn bng 1/8 lng cht phng x ban u

ca mu .

c. Trong cy ci c cht phng x C146 . phng x ca mt mu g ti v mt mu g c icng khi lng ln lt l 0,25Bq v 0,215Bq. Tnh tui ca mu g c i.

9.5.Pht pho ( P32

15 ) phng x-vi chu k bn r T = 14,2 ngy v bin i thnh lu hunh (S). Vit

phng trnh ca s phng x v nu cu to ca ht nhn lu hunh. Sau 42,6 ngy k t thi

im ban u, khi lng ca mt khi cht phng x P32

15 cn li l 2,5g. Tnh khi lng ban

u ca n.

9.6.Phn ng phn r ca urani c dng: U238

92 Pb206

82 + x + y-.

a. Tnh x v y.b.Chu k bn r ca U23892 l 4,5.109nm. Lc u c 1g U23892 nguyn cht. Tnh phng x

ban u, phng x sau 9.109nm v s nguyn t U238

92 b phn r sau 5.109nm.

9.7.Coban ( Co60

27 ) phng x-vi chu k bn r 5,27 nm v bin i thnh niken (Ni). Vit phng

trnh phn r v nu cu to ca ht nhn con. Hi sau bao lu th 75% khi lng ca mt khi

cht phng x Co6027 phn r ht.

9.8.Tm nng lng to ra khi mt ht nhn urani 234U phng x tia to thnh ng v thori 230Th.

Cho cc nng lng lin kt ring ca ht l7,10MeV; ca 234U l 7,63MeV; ca 230Th l7,70MeV.

9.9.Ht nhn triti (T) v teri (D) tham gia phn ng nhit hch sinh ra ht nhn X v ht ntron.Vit phng trnh phn ng v tm nng lng to ra t phn ng. Cho bit ht khi ca htnhn triti l mT = 0,0087u, ca ht nhn teri l mD = 0,0024u, ca ht nhn X l mX =0,0305u, 1u = 931,5 MeV/c

2.

9.10. o chu k bn r ca cht phng x, ngi ta cho my m xung bt u m t thi im t o= 0. n thi im t1 = 2gi, my m c n1xung, n thi im t2 = 3t1, my m c n2xung, vi n2 = 2,3n1. Xc nh chu k bn r ca cht phng x.


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9.11. Cho phn ng ht nhn 3717 Cl + X n +37

18 Ar.

Hy cho bit l phn ng ta nng lng hay thu nng lng. Xc nh nng lng ta ra hocthu vo. Bit khi lng ca cc ht nhn: mAr = 36,956889u; mCl = 36,956563u; mp = 1,007276u;mn = 1,008665u; u = 1,6605.10

-27kg; vn tc nh sng trong chn khng c = 3.108m/s.

9.12. Ht nhn 22688 Ra c chu k bn r 1570 nm phn r thnh 1 ht v bin i thnh ht nhn X.

a. Vit phng trnh phn ng.b.Tnh s ht nhn X c to thnh trong nm th 786. Bit lc u c 2,26g radi. Coi khi

lng ca ht nhn tnh theo u xp x bng s khi ca chng v NA = 6,02.1023mol-1.

9.13. Plni210

84 Po l mt cht phngx c chu k bn r 140 ngy m. Ht nhn plni phng x s

bin thnh ht nhn ch (Pb) v km theo mt ht . Ban u c 42mg cht phng x plni. Tnhkhi lng ch sinh ra sau 280 ngy m.

9.14. ng v 2411Na l cht phng x-v to thnh ng v ca magi. Mu 2411Na c khi lng ban

u l m0= 0,24g. Sau 105 gi, phng x ca n gim i 128 ln. Cho NA = 6,02.1023

(mol-1

).

a. Vit phng trnh phn ng.b.Tm chu k bn r v phng x ban u.c. Tm khi lng magi to ra sau thi gian 45 gi.

9.15. Cho phnng ht nhn 23090 Th226

88 Ra + X + 4,91MeV.

a.Nu cu to ca ht nhn X.b.Tnh ng nng ca ht nhn Ra. Bit ht nhn Th ng yn. Ly khi lng gn ng ca cc

ht nhn tnh bng n v u c gi tr bng s khi ca chng.

9.16. Cho phn ng ht nhn 94 Be +1

1 H X +6

3Li

a. X l ht nhn ca nguyn t no v cn gi l ht g?b.

Hy cho bit l phn ng ta nng lng hay thu nng lng. Xc nh nng lng ta rahoc thu vo. Bit mBe = 9,01219u; mp = 1,00783u; mLi = 6,01513u; mX = 4,0026u; 1u =931MeV/c

2.

9.17. Dng 1 prton c ng nng Wp= 5,58MeV bn ph ht nhn23

11Na ng yn sinh ra ht v

X. Coi phn ng khng km theo bc x .a. Vit phng trnh phn ng v nu cu to ht nhn X.b.Phn ng trn thu hay ta nng lng. Tnh nng lng .c. Bit ng nng ca ht l W = 6,6MeV. Tnh ng nng ca ht nhn X.

9.18. Bn ht c ng nng 4MeV vo ht nhn 147 N ng yn th thu c mt ht prton v mt

ht nhn X.a. Vit phng trnh phn ng, nu cu to ca ht nhn X v tnh xem phn ng ta ra hay thu

vo bao nhiu nng lng.

b.Gi s hai ht sinh ra c cng tc , tnh ng nng v tc ca prton. Cho: m = 4,0015u;mX = 16,9947u; mN = 13,9992u; mp = 1,0073u; 1u = 931MeV/c

2; c = 3.108m/s.

Bi trc nghim:


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L thuyt

Cu 1: Nng lng lin kt ca ht l 28,4MeV, ca ht 2311 Na l 186,6MeV. Ht23

11 Na bn vng hn htl do:

A. ht nhn no c nng lng lin kt ln hn th bn vng hn

B. l ng v phng x cn 2311 Na l ng v bnC

. ht nhn c s khi cng ln th cng bn vngD. ht nhn c nng lng lin kt ringcng ln th cng bn vngCu 2: Chn cu ng.

A. Ht nhn cngbn khi ht khi cng ln.B. Khi lng ca ht nhn bng tng khi lng ca cc nucln C. Trong ht nhn s prtn lun lun bng s ntrn.D. Khi lng ca prtn ln hn khi lng ca ntroon.

Cu 3: ng v v l nhng nguyn t m ht nhnA. c th phn r phng x B. c cng s prtn ZC. c cng s ntron N D. c cng s nucln A

Cu 4: Chu k bn r T ca mt cht phng x l khong thi gian no? A. Sau , s nguyn t phng x gim i mt na

B. Bng qung thi gian khng i, sau , s phng x lp li nh ban u C. Sau , cht y mt hon ton tnh phng xD. Sau , phng x ca cht gim i 4 ln

Cu 5: Trong phng x , ht nhn m so vi ht nhn con c v tr th no?A. Tin 1 trong bngtun hon B. Tin 2 trong bng tun honC. Li 1 trong bng tun hon D. Li 2 trong bng tun hon

Cu 6: iu no sau y ng khi ni v tia ?

A. Ht c cng khi lng vi lectronnhng mang in tch nguyn t dng.

B. Tia c tm bay ngn hn so vi tia .

C. Tia c kh nng m xuyn rt mnh, ging nh tia Rn ghen.

D. A, B v C u ng.Cu 7: iu no sau y sai khi ni v tia ?

A. Tia thc cht l ht nhn nguyn t hliB. Khi i qua in trng gia hai bn t in, tia b lch v pha bn m ca t inC. Tia phngra t ht nhn vi vn tc bng vn tc nh sngD. Tia ch i c ti a 8cm trong khng kh

Cu 8: Trong cc loi tia phng x sau, tia m xuyn yu nht l tia no? A. Tia B. Tia + C. Tia - D. Tia

Cu 9: Trong cc loi tia phng x, tia no khng mang in? A. Tia B. Tia + C. Tia - D. Tia

Cu 10: Chn cu tr li sai

A. Ntrin l ht s cp B. Ntrin xut hin trng s phn r phng xC. Ntrin xut hin trng s phn r phng x D. Ntrin ht khng c in tch

Cu 11: C th tng hng s phn r ca ng v phng x bng cch no?A. t ngun phng x vo trong t trng mnh B. t ngun phng x vo trong in trng mnhC. t nng ngun phng x D. Hin nay ta khng bit cch no c th lmthay i hng s phn r phng x

Cu 12: Trong cc phn ng ht nhn, i lng no c bo ton? A. Tng s prtn B. Tng s nuclnC. Tng s ntron D. Tng khi lng cc ht nhn

Cu 13: Cc phn ng ht nhn khng tun th theo cc nh lut no sau y?


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A. Bo ton nng lng ton phn B. Bo ton in tchC. Bo ton ng lng D. Bo ton khi lng

Cu 14: Trong mt phn ng ht nhn, tng khi lng cc ht tham gia s nh th no? A. c bo ton B. Tng, hoc gim tu theo phn ngC. Gim D. Tng

Cu 15: Phn ng nhit hch l phn ng ht nhnA

. to mt lng nhit lnB

. cn mt nhit rt cao mi thchin cC. hp th mt nhit lng ln D. ht nhn cc nguyn t b nung chy thnh ccnucln

Cu trc ht nhnCu 16: Ht nhn nguyn t c cu to bi nhng ht no?

A. Prtn B. Ntrn C. Prton v ntrn D. Prton, ntrn vlectron

Cu 17: Tnh s nguyn t trong 1g O2 cho23

AN 6,022.10 ht/mol; O = 16.A. 376.1020nguyn t B. 736.1020nguyn tC. 637.1020nguyn t D. 367.1020nguyn t

Cu 18: S prtn trong 15,9949 gam 168

O l bao nhiu?

A.244,82.10 B.

236,023.10 C.2396,34.10 D.

2414,45.10

Cu 19: Cho s Avogadro NA = 6,02.1023

mol-1. S ht nhn nguyn t c trong 100g it phng x ( 13153I )l bao

nhiu?

A. 3,592.1023ht B. 4,595.1023ht C. 4,952 .1023ht D.5,426 .1023htCu 20: Chn cu ng. Ht nhn liti c 3 prtn v 4 ntron. Ht nhn ny c k hiu nh th no?

A.7

3Li B.

4

3Li C.

3

4 Li D.3

7Li

Cu 21: Ht nhn nguyn t ch c 82 prtn v 125 ntron. Ht nhn nguyn t ny c k hiu nh th no?

A.125

12 Pb B.12

125 Pb C.82

207 Pb D.207

82 Pb

Cu 22: Cho 4 ht nhn nguyn t c k hiu tng ng 2 3 3 41 1 2 2D, T, He, He.Nhng cp ht nhn no l cc

ht nhn ng v?A.

2

1D v

3

2He B.

2

1D v

4

2He C.

2

1D v

4

2He D.

2

1D v

3

1T

Cu 23: Khi lng ca ht nhn 104 Be l 10,0113u; khi lng ca prtn m p = 1,0072u, ca ntron m n =

1,0086; 1u = 931 MeV/c2 . Nng lng lin kt ring ca ht nhn ny l bao nhiu?

A. 6,43 MeV B. 6,43 MeV C. 0,643 MeV D. Mt gi tr khc

Cu 24: Ht nhn 2010 Ne c khi lng Nem 19,986950u . Cho bit p nm 1,00726u;m 1,008665u; 21u 931,5MeV / c . Nng lng lin kt ring ca 2010 Ne c gi tr l bao nhiu?

A. 5,66625eV B. 6,626245MeV C. 7,66225eV D. 8,02487MeV

Cu 25: ng v phng x cban 6027 Co pht ra tia- v tia . Bit Co nm 55,940u;m 1,008665u;

pm 1,007276u . Nng lng lin kt ca ht nhn cban l bao nhiu?

A.10E 6, 766.10 J B.

10E 3, 766.10 J

C.10E 5, 766.10 J D.

10E 7, 766.10 J

Cu 26: Cho ht nhn 42 He ln lt c khi lng 4,001506u, mp=1,00726u, mn=1,008665u, u=931,5MeV/c2. Nng

lng lin kt ring ca ht nhn 42 He c gi tr l bao nhiu?

A. 7,066359 MeV B. 7,73811 MeV C. 6,0638 MeV D. 5,6311 MeV

Cu 27: Tnh nng lng lin kt ring ca ht nhn 3717

Cl . Cho bit: mp = 1,0087u; mn = 1,00867u; mCl =

36,95655u; 1u = 931MeV/c2


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A. 8,16MeV B. 5,82 MeV C. 8,57MeV D. 9,38MeV

Cu 28: Bit khi lng ca ht nhn U238 l 238,00028u, khi lng ca prtn v ntron l mP=1.007276U;mn = 1,008665u; 1u = 931 MeV/ c

2. Nng lng lin kt ca Urani 23892 U l bao nhiu?

A. 1400,47 MeV B. 1740,04 MeV C.1800,74 MeV D. 1874 MeV

Phng x

Cu 29: Thi gian bn r ca 9038 Sr l T = 20 nm. Sau 80 nm, s phn trm ht nhn cn li cha phn r lbao nhiu?

A. Gn 25% B. Gn 12,5% C. Gn 50% D. Gn 6,25%Cu 30: Mt ngun phng x c chu k bn r T v ti thi im ban u c 32N 0ht nhn. Sau cc khong thigian T/2, 2T v 3T, s ht nhn cn li ln lt bng bao nhiu?

A. 0 0 024N ,12N ,6N B. 0 0 016 2N ,8N ,4N

C. 0 0 016N ,8N ,4N D. 0 0 016 2N ,8 2N , 4 2N

Cu 31: Mt ngun phng x c chu k bn r T v ti thi im ban u c 48N oht nhn. Hi sau khong thigian 3T, s ht nhn cn li l bao nhiu?

A. 4N0 B. 6N0 C. 8N0 D. 16N0

Cu 32: Chu k bn r ca14

6 C l 5570 nm. Khi phn tch mt mu g, ngi ta thy 87,5% s nguyn t ngv phng x C14 b phn r thnh cc nguyn t 147 N . Tui ca mu g ny l bao nhiu?

A. 11140 nm B. 13925 nm C. 16710 nm D. Phng n khc

Cu 33: Radon l cht phng x c chu k bn r T = 3,6 ngy. Ti thi im ban u c 1,2g 22286 Rn , sau

khong thi gian t = 1,4T s nguyn t 22286 Rn cn li l bao nhiu?A. 1,874.1018 B. 2,165.1018 C. 1,234.1018 D. 2,465.1018

Cu 34: C bao nhiu ht -c gii phng trong mt gi t mt micrgam (10 -6g) ng v 2411 Na , bit ng v

phng x -vi chu k bn r T = 15 gi.

A.15N 2,134.10 % B.

15N 4,134.10 % C.15N 3,134.10 % D.

15N 1,134.10 %

Cu 35: Radon l cht phng x c chu k bn r T = 3.6 ngy. Ti thi im ban u c 1,2 g222

86Rn , sau

khong thi gian t = 1,4T s nguyn t 22286Rn cn li l bao nhiu?

A. N = 1.874. 1018

B. N = 2,615.1019

C. N = 2,234.1021

D. N = 2,465.1020

Cu 36: Mt cht phng x c hng s phn r bng 1,44.10 -3(1/gi). Sau thi gian bao lu th 75% s htnhn ban u b phn rht?

A. 36ngy B. 37,4ngy C. 39,2ngy D. 40,1ngy

Cu 37: Chu k bn r210

84 Po l 318 ngy m. Khi phng x tia , plni bin thnh ch. C bao nhiu nguyn

t plni b phn r sau 276 ngy trong 100mg 21084 Po ?

A.200,215.10 B.

202,15.10 C.200,215.10 D.

201,25.10

Cu 38: phng x 6027Cophn r ht l bao nhiu?A. 2,35nm B.2,57nm C. 7.905 nm D. 10.54 nm

Cu 39: cho chu k bn r T ca mt cht phng x, ngi ta dng my m xung. Trong t 1gi u tin my

m c n1xung; trong t2 = 2t1 gi tip theo my m c 2 19

n n64

xung. Chu k bn r T c gi tr l bao

nhiu?

A. T = t1/2 B. T = 1t

3 C. T = 1t

4 D. T = 1t

6

Cu 40: Urani (238

92U ) c chu k bn r l 4,5.109nm. Khi phng x , urani bin thnh thri ( 23490Th ). Khi

lng thri to thnh trong 23,8 g urani sau 9.109nm l bao nhiu?A. 17,55g B. 18,66g C. 19,77g D.Phng n khc


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Cu 41: Bit chu k bn r ca it phng x ( 13153I ) l 8 ngy m. Ban u c 100g it phng x. Khi lng

cht it cn li sau 8 tun l l bao nhiu?A. 0,391g B.0,574g C. 0,781g D. 0,864g

Cu 42: Plni (Po210) l cht phng x c chu k bn r T = 138 ngy. Mt mu Plni nguyn cht c khilng ban u l 0,01 g. phng x ca mu cht trn sau 3 chu k bn r l bao nhiu?

A. 16,32.1010

Bq B. 18,49.109

Bq C. 20,84.1010

Bq D. Mt p n khc.

Cu 43:22688 Ra l cht phng x , vi chu k bn r T = 1570 nm (1 nm = 365 ngy). phng x ca 1g

radi l:

A.10

0H 7,37.10 Bq B.10

0H 7,73.10 Bq

C.10

0H 3,73.10 Bq D.14

0H 3,37.10 Bq

Cu 44: Cht phng x plni (Po210) c chu k bn r 138 ngy. Tnh lng plni c phng x l 1Ci. A. 1018nguyn t B. 50,2.1015nguyn tC. 63,65.1016nguyn t D. 30,7.1014nguyn t

Cu 45: Mt gam cht phng x trong 1s pht ra 4,1. 1013ht . Khi lng nguyn t ca cht phng x nyl 58,933u; 1u = 1,66.10

-27kg. Chu k bn r ca cht phng x ny l bao nhiu?

A. 1,78.108

s B. 1,68.108

s C. 1,86.108

s D. 1,87.108s

Cu 46: Ban u c m0 = 1mg cht phng x radon ( 222 Rn ). Sau 15,2 ngy th phng x ca n gim93,75%, phng x H ca n khi l bao nhiu?

A. H= 0,7553.1012 Bq B. H= 0,3575. 1012 Bq

C. H = 1,4368.1011 Bq D. ps khc.

Cu 47: Ban u c 5 g radon 22286 Rn l cht phng x vi chu k bn r T = 3,8 ngy. phng x ca lng

radon ni trn sau thi gian 9,5 ngy l:A. 1,22.10

5Ci B. 1,36.10

5Ci C. 1,84.10

5Ci D. Phng n khc

Cu 48:200

79 Au l mt cht phng x. Bit phng x ca 3.10-9kg cht l 58,9 Ci, ln2 = 0,693; ln10 = 2,3.

Chu k bn r cua Au200 l bao nhiu ?

A. 47,9 Pht B. 74,9 pht C. 94,7 pht D. 97,4pht

Cu 49: ng v

24

11 Na l cht phng x-

v to thnh ng v ca magie. Mu

24

11 Na c khi lng ban u0m 0, 24g . Sau 105 gi, phng x ca n gim i 128 ln. Chu k bn r ca Na24 l

Cu 50: Cht phng x plni (Po210) c chu k bn r 138 ngy. Tnh lng plni c phng x l 1Ci.A. 1018nguyn t B. 50,2.1015nguyn tC. 63,65.1016nguyn t D. 30,7.1014nguyn t

Cu 51: ng v phng x 6629 Cu c thi gian bn r T = 4,3 pht. Sau thi gian t = 1,29 pht, phng x ca

ng v ny gim xung cn bao nhiu?A. 85% B. 87,5% C. 82,5% D. 80%

Cu 52: Radon l cht phng x c chu k bn r T = 3,6 ngy. phng x ban u ca 1,2 g 22286 Rn l bao

nhiu?

A. 1,234.1012 Bq B. 7,255.1015 Bq C. 2,134.1016 Bq D. 8,352.1019 Bq

Cu 53: Khi phn tch mt mu g, ngi ta thy 87,5% s nguyn t ng v phng x 146C b phn r thnh

cc nguyn t 177N . Bit chu k bn r ca14

6C l 5570 nm. Tui ca mu g ny l bao nhiu?

A. 1760 nm B. 111400 nm C. 16710 nm D. Mt s p s khc

Cu 54: Cho bit 23892U v235

92U l cc cht phng x c chu k bn r ln lt l T1 = 4,5.109 nm v

T2=7,13.108nm. Hin nay trong qung urani thin nhin cln U238 v U 235 theo t l 160 : 1. Gi thit thi

im to thnh Tri t t l 1:1. Cho ln10 = 2,3; ln2 = 0,693. Tui ca Tri t l bao nhiu?A. 4,91.10

9nm B. 5,48.109nm C. 6,20.109nm D. 7,14.109nm


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Cu 55: phng x 14 Ctrong mt tng g c bng 0,65 ln phng x ca 14 Ctrong mt g cng khilng va mi cht. Chu k bn r ca 14 Cl 5700 nm. Tui ca tng g c l bao nhiu nm?

A. 3521 nm B. 4352 nm C. 3542nm D. p n khc

Cu 56:238

92 U sau nhiu ln phng x ht v-bin thnh ch 20682 Pb . Bit chu k bn r ca s bin i tng

hp ny l T = 4,6.109nm. Gi s ban u mt loi ch cha urani, khng c ch. Nu hin nayt l cc khilng ca U238 v Pb206 l 37 th tui ca y l bao nhiu nm?

A. 2.107nm B. 2.108nm C. 2.109nm D. 2.1010nm

Phn ng ht nhn

Cu 57: Ht nhn nguyn t ca nguyn t AZ X b phn r v kt qu l xut hin ht nhn nguyn t no?

A.A 2

Z 2 Y B.A 4

Z 2 Y C.A 1

Z Y D.A

Z 1 Y

Cu 58: Phn ng phn r uran c dng 238 20692 82U Pb x y , trong x v y c gi tr l bao nhiu?

A. x = 8; y = 6 B. x =6; y = 8 C. x = 7; y =9 D. x = 9; y =7

Cu 59: Chn cu ng. Phng trnh phng x: 10 A 85 Z 4B X Be . Trong Z, A c gi tr:A. Z = 0; A = 1 B. Z = 1; A = 1 C. Z = 1; A = 2 D. Z = 2; A = 4

Cu 60: Cho phn ng ht nhn235 93

92 41 3 7A

ZU n X Nb n . A v Z c gi tr l bao nhiu?A. A = 142, Z = 56 B. A= 139; Z = 58 C. A = 133; Z = 58 D. A = 138; Z = 58.

Cu 61: ng v phng x 2714 Si chuyn thnh27

13 Al phng ra:

A. Ht B. Ht pzitn C. Ht lectron D. Ht prtn

Cu 62: Cho phn ng ht nhn: 37 1 3717 1 18Cl H n Ar . Cho bit khi lng ht nhn Clm 36,956563u ,

Ar p nm 36,956889u,m 1,00727u;m 1,008670u . Phn ng s l phn ng g?

A. To nng lng 1,6MeV B. Thu nng lng 2,3MeVC. To nng lng 2,3MeV D. Thu nng lng 1,6MeV

Cu 63: Cho phn ng ht nhn: 23 4 2011 2 10 Na p He He. Bit khi lng ht nhn mNa = 22,983734u, mHe =

4,00 11506u, mp = 1,007276u, mNe= 19,986950u. Phn ng ny l phn ng g?A. Thu nnglng 2,45 MeV B. Thu nng lng 1,45 MeVC. To nng lng 2,71 MeV D. To nng lng 2,45 MeV.

Cu 64: Nng lng trung bnh to ra khi phn hch mt ht nhn 23592U l 200MeV. Mt nh my in

nguyn t dng nguyn liu urani trn c cng sut 500MW, hiu sut 20%. Khi lng urani tiu th hng nmca nh my trn l bao nhiu?

A.865,12kg B. 926,74kg C. 961,76kg D. p s khc

Cu 65:235 95 139

92 42 57 2U n Mo La n l mt phn ng phn hch ca Urani 235. Bit khi lng ht nhn:

mN = 234,99u; mNo = 94,88u; m La =138,87u; mn= 1,0087u. Cho nng sut to nhit ca xng l 46.106J/kg. Khi

lng xng cn dng c th to ra nng lng nh 1g Urani l bao nhiu? A. 1616 kg B. 1717 kg C. 1818 kg D. 1919 kg

Cu 66: Nguyn t plni 21084 Po phng x v bin i thnh nguyn t ch (Pb). Bit Pom 209,937304u ,

Pb Hem 205, 929442u, m 4, 0 01506 u . Nng lng ta ra bi phn ng ht nhn l bao nhiu?

A. E 5,2MeV B. E 3,2 MeV C. E 5,92 MeV D. E 3,6 MeV

Cu 67: Cho nng lng lin kt ringca l 7,10 MeV, ca urani U234 l 7,63 MeV, ca thri Th230 l 7,70MeV. Nng lng to ra khi mt ht nhn U234phng x to thnh Th230 l bao nhiu?

A. 12MeV B.13MeV C. 14MeV D. 15MeV

Cu 68: Cho phn ng ht nhn: 7 4 43 2 2 Li p He He. Bit mLi = 7,0144u; mp = 1,0073u; m = 4,0015u.

Nng lng to ra trong phn ng l bao nhiu?A. 20 MeV B. 16MeV C. 17,4 MeV D. 10,2 MeV


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Cu 69: Nng lng ti thiu cn thit chia ht nhn 126 C thnh ba ht (cho Cm 12,000u, 2m 4,0015u,1u 931MeV / c ) c gi tr l bao nhiu?

A. 2,1985MeV B. 3,8005MeV C. 4,1895MeV D. 4,8915MeV

Cu 70: Ht nhn phng x 23492 U ng yn pht ra ht theo phng trnh234 4 A

92 2 ZU He X . Nng lng ta

ra ca phn ng ny l 14,15MeV. Xem khi lng ht nhn gn ng bng s khi tnh theo n v u. ng nng

ca ht l bao nhiu?A. 13,72MeV B. 12,91MeV C. 13,91MeV D. 12,79MeV

Cu 71:226

88 Ra l cht phng x , vi chu k bn r T = 1570 nm (1 nm = 365 ngy). Phng x trn ta ra

nhit lng 5,96MeV. Gi s ban u ht nhn radi ng yn. Tnh ng nng ca ht v ht nhn con sau phnng. Cho khi lng ht v ht nhn con tnh theo n v u bng s khi ca chng.

A. xK 1,055MeV;K 4,905MeV B. xK 4,905MeV;K 1,055MeV

C. xK 5,855MeV;K 0,1055MeV D. xK 0,1055MeV;K 5,855MeV

Cu 72: Dng pttn c WP= 1,20 MeV bn vo ht nhn7

3 Li ng yn th thuc hai ht nhn4

2 He c cng

vn tc. Cho mP = 1,0073u; mLi = 7,0140u; mHe = 4,0015u v 1 u = 931MeV/c2. ng nng ca mi ht 42 He l:

A. 0,6MeV

B. 7,24MeV

C. 8,52MeV

D. 9,12MeV

Cu 73: Bn ht nhn c ng nng W vo ht nhn 147 N ng yn ta c:14 17

7 8N O p . Bit2

p N Om 4,0015u;m 1,0072u;m 13,9992u;m 16,9947u;1u 931MeV / c ; cc ht nhn sinh ra cng

vn tc. ng nng prtn sinh ra c gi tr l bao nhiu?

A.p

1W W

48 B.

p

1W W

81 C.

p

1W W

62 D.

p

1W W

45 Cu 74: Xt phn ng ht nhn xy ra khi dng ht bn ph nhn: 27 3013 15 Al P n. Bit khi lng ht

nhn : MAl = 26, 974u; mp = 29,97u; mn= 1,0087u. Nng lng ti thiu ca ht phn ng xy ra l baonhiu?

A. 2,35 MeV B. 3,17MeV C. 5,23 MeV D. 6,21 MeV

Cu 75: Bn ht nhn c ng nng 18 MeV vo ht nhn14

7 N ng yn ta c phn ng14 17

7 8N O p .Bit cc ht nhn sinh ra cng vc t vn tc. Cho m = 4,0015u; m p = 1,0072u; m N = 13,9992u; m O =16,9947u;

cho u = 931 MeV/c2. ng nng ca ht prtn sinh ra c gi tr l bao nhiu? A. 0,111 MeV B. 0,222MeV C. 0,333 MeV D. 0,444 MeV

vat li hat nhan_li thuyet va bai tap

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