Giai Theo d i n h l u a t Xtoc, a n h sang k i c h t h i c h p h a i c6 h'Jdc song nho hcfn hiXdc song a n h sang p h a t quang Trong cac hiidc song t r e n t h i hu6c song CO g i a t r i 0,60 p m k h o n g the phat quang Vqy chon dap an D Cdu 51: P o l o n i ^^Po phong xa a va b i e n d d i t h a n h c h i Pb Biet k h o i lUcfng cac h a t n h a n Po; u ; Pb I a n \\iat l a : 209,937303u; 4,001506u; MeV 205,929442u v a l u = 931,5 — — N a n g liTcfng t o a r a k h i m o t h a t n h a n c poloni p h a n r a x a p x i bang: D 2,96 MeV C 5,92 M e V B 29,60 MeV A 59,20 M e V Giai Do h u t k h o i : Am = mp^ - (n^Pb + ) = 209,937303U - 205,929442u -4,001506u = 0,006355u AE = A m c ' = , 9 « 5,92 MeV Vay chgn dap an C Cdu 52: M p t scfi d a y chieu d a i i cSng ngang, h a i dau co d i n h T r e n day dang c6 song d t o g v o i n b u n g song, toe t r u y e n song t r e n day la v K h o a n g t h d i g i a n giuTa h a i I a n l i e n tiep scfi day duoi t h a n g l a : A ^ n£ B 5^ C ^ 2nv £ D ' nv GiSi Ydi I l a hudc song t h i - = - = > > = — n n \ Chu k i dao dong: T = - = — V nv K h o a n g thcfi gian giufa h a i I a n l i e n t i e p scri day du6i t h i n g l a : nv • Vay chgn dap an D 102 Giiichitigt