Prof : AZIZ HALIBPage 253102 / 3103 I . 1 ) . Z A . X AZX N=A- Z . : 3517Cl 17 35 18 . Kg C-27 1.6726 10-19 1.6 10-27 1.6749 10 02 ) .A Z . : 146C 126C ,168O . . A . 3 ) Z A . : 11H 21H 31H . . 11H21H31H99.985% 0.015% 0.0001%4 ) r A : 130r =r A -150 r =1.2 10 m . .3 3 30 0 M m A 3m A 3m= = = =4V 4.r .A 4.r .r317 3 8 32.10 kg/ m =2.10 tonne/ cm-27 m=1.7 10 kg . 31cm 200 . 5 ) N,Z (Sgr) . : . )(. Z 20 ( ) NZ . Z 20 . 64 224 34 .II . 1Prof : AZIZ HALIBPage 263102 / 3103 . . : - + .1 ) Z A .1 2 3 41 2 34A A A AZ Z ZZX+ XX+ X :1 2 3 4Z +Z =Z +Z 1 2 3 4A +A =A +A2 ) AZX Y 42He . : A A-4 4Z Z-2 2X Y +He :238 234 492 90 2UTh+ He (A 200) .3 ) - AZX Y - . : A A -Z Z+1X Y + . : 14 14 -6 7CN+ - . : - -10e .4 ) + AZX Y + . : A A +Z Z-1X Y + . : 13 14 +7 7NN + : .+ 0+1e . + . 5 ) - + ) ( ) ( .*X . ( 1810 Hz .) : A * AZ ZX X + . III . 0N t =0 . t :-t0 N(t) =N e 0N . -t0 N(t) =N e 1 ) 1 = . t = . -t - -10 0 0 N(t) =N e N() =Ne N() =Ne 0 0N() =0.37N N() =37%N t = 37% 63% . 63% . 2 ) 12t . 12t1 12 2-t -t01 0 02 NN(t ) =N e =N e22Prof : AZIZ HALIBPage 273102 / 31031 12 2-t -t1 1e = ln(e ) =ln( )2 212ln(2)t =- =- ln(2). 12t . t =0 t = .3 ) a . :dN(t)a(t) =-dt. -t0 N(t) =N e : -t0d da(t) =- N(t) =- N edt dt -t -t -t0 0 0d=-N e = N e =a edt-t0 a(t) a e 0 0a N t =0 . a (Bq) . : AAN(t)n(t) = N(t) N n(t)N t AN . t =0 00 0 0 AANn = N N nN .-t0 N(t) =N e 0 -tA A N n(t) N n e 0-t n(t) n e . m(t)n(t) =M00mn =M 0-t m(t) m e .0m t =0 m(t) t .IV .

. . : 232 . V . ... . . . 14 14 12 . 146C :14 14 06 7 -1C N+ e a(t) 0a t =0 t : -t0 a(t) a e -t0 0a(t) a(t)=e ln( ) =-ta a 10 0 2 ta a1t =ln( ) =ln( )a(t) a(t) ln(2).3