\u00a0Ph\u00f3ng x\u1ea1 l\u00e0 m\u1ed9t d\u1ea1ng to\u00e1n d\u1ec5 trong ch\u01b0\u01a1ng tr\u00ecnh v\u1eadt l\u00fd h\u1ea1t nh\u00e2n v\u00e0 d\u1ec5 \u0103n \u0111i\u1ec3m t\u1ed1i \u0111a trong c\u00e1c \u0111\u1ec1 thi ch\u1ec9 c\u1ea7n b\u1ea1n n\u1eafm ch\u1eafc l\u00fd thuy\u1ebft v\u00e0 c\u00e1c d\u1ea1ng b\u00e0i to\u00e1n v\u1ec1 ph\u00f3ng x\u1ea1 h\u1ea1t nh\u00e2n<\/p>\n

V\u1edbi d\u1ea1ng b\u00e0i to\u00e1n v\u1ec1 ph\u00f3ng x\u1ea1 h\u1ea1t nh\u00e2n, c\u00e1c b\u1ea1n c\u1ea7n n\u1eafm r\u00f5 v\u1ec1 c\u00e1c ph\u1ea7n l\u00fd thuy\u1ebft sau:<\/p>\n

+ X\u00e1c \u0111\u1ecbnh l\u01b0\u1ee3ng ch\u1ea5t ph\u00f3ng x\u1ea1 c\u00f2n l\u1ea1i ho\u1eb7c b\u1ecb ph\u00e2n r\u00e3.<\/p>\n

+ X\u00e1c \u0111\u1ecbnh chu k\u1ef3 b\u00e1n r\u00e3 ho\u1eb7c h\u1eb1ng s\u1ed1 ph\u00f3ng x\u1ea1<\/p>\n

+ X\u00e1c \u0111\u1ecbnh \u0111\u1ed9 ph\u00f3ng x\u1ea1 v\u00e0 tu\u1ed5i c\u1ee7a m\u1eabu v\u1eadt b\u1eb1ng nhi\u1ec1u ph\u01b0\u01a1ng ph\u00e1p kh\u00e1c nhau.<\/p>\n

– Ngo\u00e0i ra, c\u00e1c b\u1ea1n c\u1ea7n n\u1eafm r\u00f5 c\u00e1c d\u1ea1ng b\u00e0i to\u00e1n v\u1ec1 ph\u00f3ng x\u1ea1 h\u1ea1t nh\u00e2n kh\u00e1c li\u00ean quan \u0111\u1ebfn hi\u1ec7n t\u01b0\u1ee3ng ph\u00f3ng x\u1ea1 nh\u01b0 l\u00e0 n\u0103ng l\u01b0\u1ee3ng ph\u1ea3n \u1ee9ng, v\u1eadn t\u1ed1c c\u1ee7a c\u00e1c h\u1ea1t sinh ra, g\u00f3c t\u1ea1o th\u00e0nh gi\u1eefa c\u00e1c h\u1ea1t sau ph\u1ea3n \u1ee9ng\u2026\u0111\u1ec3 kh\u00f4ng b\u1ecb b\u1ee1 ng\u1ee1 khi g\u1eb7p nh\u1eefng d\u1ea1ng to\u00e1n \u0111\u00f3.<\/p>\n

I. L\u00fd thuy\u1ebft chung \u0111\u1ec3 gi\u1ea3i c\u00e1c d\u1ea1ng b\u00e0i to\u00e1n v\u1ec1 ph\u00f3ng x\u1ea1 h\u1ea1t nh\u00e2n:<\/h3>\n

\n
1. Hi\u1ec7n t\u01b0\u1ee3ng ph\u00f3ng x\u1ea1:<\/strong><\/li>\n<\/ol>\n

   – Ph\u00f3ng x\u1ea1 l\u00e0 qu\u00e1 tr\u00ecnh ph\u00e2n r\u00e3 t\u1ef1 ph\u00e1t c\u1ee7a m\u1ed9t h\u1ea1t nh\u00e2n kh\u00f4ng b\u1ec1n v\u1eefng (t\u1ef1 nhi\u00ean hay nh\u00e2n t\u1ea1o). Qu\u00e1 tr\u00ecnh ph\u00e2n r\u00e3 n\u00e0y k\u00e8m theo s\u1ef1 t\u1ea1o ra c\u00e1c h\u1ea1t v\u00e0 c\u00f3 th\u1ec3 k\u00e8m theo s\u1ef1 ph\u00e1t ra c\u00e1c b\u1ee9c x\u1ea1 \u0111i\u1ec7n t\u1eeb. H\u1ea1t nh\u00e2n t\u1ef1 ph\u00e2n r\u00e3 g\u1ecdi l\u00e0 h\u1ea1t nh\u00e2n m\u1eb9, h\u1ea1t nh\u00e2n \u0111ue\u1ecdc t\u1ea1o th\u00e0nh sau ph\u00e2n r\u00e3 g\u1ecdi l\u00e0 h\u1ea1t nh\u00e2n con.<\/p>\n

   \n
   1. C\u00e1c d\u1ea1ng ph\u00f3ng x\u1ea1:<\/strong><\/li>\n<\/ol>\n

      2.1 Ph\u00f3ng x\u1ea1\u00a0:<\/p>\n

      – L\u00e0 qu\u00e1 tr\u00ecnh m\u1ed9t h\u1ea1t nh\u00e2n m\u1eb9 ph\u00f3ng ra m\u1ed9t h\u1ea1t nh\u00e2n\u00a0\u00a0v\u00e0 bi\u1ebfn \u0111\u1ed5i th\u00e0nh h\u1ea1t nh\u00e2n kh\u00e1c.<\/p>\n

      – D\u1ea1ng ph\u01b0\u01a1ng tr\u00ecnh c\u1ee7a ph\u00f3ng x\u1ea1 \u221d\u00a0:\u00a0<\/p>\n

      – \u0110\u1eb7c \u0111i\u1ec3m tia \u221d\u00a0:<\/p>\n

      + Tia\u00a0 \u221d\u00a0l\u00e0 d\u00f2ng c\u00e1c h\u1ea1t nh\u00e2n\u00a0\u00a0chuy\u1ec3n \u0111\u1ed9ng v\u1edbi t\u1ed1c \u0111\u1ed9 v\u00e0o kho\u1ea3ng 20000 km\/s (2.107\u00a0m\/s).<\/p>\n

      + L\u00e0m ion h\u00f3a kh\u00f4ng kh\u00ed.<\/p>\n

      + B\u1ecb l\u1ec7ch v\u1ec1 b\u1ea3n \u00e2m c\u1ee7a t\u1ee5 \u0111i\u1ec7n.<\/p>\n

      + \u0110i \u0111\u01b0\u1ee3c kho\u1ea3ng v\u00e0i cm trong kh\u00f4ng kh\u00ed v\u00e0 ch\u1eebng v\u00e0i micromet trong v\u1eadt r\u1eafn.<\/p>\n

      2.2 Ph\u00f3ng x\u1ea1 \u03b2^{– <\/sup>:<\/p>\n}

      – L\u00e0 qu\u00e1 tr\u00ecnh m\u1ed9t h\u1ea1t nh\u00e2n m\u1eb9 ph\u00f3ng ra m\u1ed9t electron v\u00e0 bi\u1ebfn \u0111\u1ed5i th\u00e0nh h\u1ea1t nh\u00e2n kh\u00e1c.<\/p>\n

      – D\u1ea1ng c\u1ee7a ph\u01b0\u01a1ng tr\u00ecnh ph\u00f3ng x\u1ea1\u00a0 \u03b2^{–<\/sup>:\u00a0<\/p>\n}

      – Th\u1ef1c ch\u1ea5t c\u1ee7a ph\u00f3ng x\u1ea1\u00a0 \u03b2^{–<\/sup>\u00a0l\u00e0 trong h\u1ea1t nh\u00e2n, 1 notron bi\u1ebfn \u0111\u1ed5i th\u00e0nh 1 proton, 1 e-\u00a0v\u00e0 1 ph\u1ea3n notrino\u00a0<\/p>\n}

      –\u00a0\u00a0l\u00e0 ph\u1ea3n notrino, kh\u00f4ng mang \u0111i\u1ec7n, c\u00f3 s\u1ed1 kh\u1ed1i A = 0, chuy\u1ec3n \u0111\u1ed9ng v\u1edbi v\u1eadn t\u1ed1c \u00e1nh s\u00e1ng.<\/p>\n

      – \u0110\u1eb7c \u0111i\u1ec3m tia\u00a0\u03b2^{– <\/sup>:<\/p>\n}

      + Tia\u00a0\u03b2^{– <\/sup>\u00a0l\u00e0 d\u00f2ng c\u00e1c electron chuy\u1ec3n \u0111\u1ed9ng v\u1edbi v\u1eadn t\u1ed1c g\u1ea7n b\u1eb1ng t\u1ed1c \u0111\u1ed9 \u00e1nh s\u00e1ng.<\/p>\n}

      + L\u00e0m ion h\u00f3a kh\u00f4ng kh\u00ed y\u1ebfu h\u01a1n tia\u00a0, n\u00ean kh\u1ea3 n\u0103ng \u0111\u00e2m xuy\u00ean l\u1edbn h\u01a1n.<\/p>\n

      + B\u1ecb l\u1ec7ch v\u1ec1 b\u1ea3n d\u01b0\u01a1ng c\u1ee7a t\u1ee5 \u0111i\u1ec7n<\/p>\n

      + \u0110i \u0111\u01b0\u1ee3c kho\u1ea3ng v\u00e0i met trong kh\u00f4ng kh\u00ed, v\u00e0i milimet trong kim lo\u1ea1i.<\/p>\n

      2.3 Ph\u00f3ng x\u1ea1 \u03b2^{+<\/sup>\u00a0:<\/p>\n}

      – L\u00e0 qu\u00e1 tr\u00ecnh m\u1ed9t h\u1ea1t nh\u00e2n m\u1eb9 ph\u00e1t ra m\u1ed9t pozitron v\u00e0 bi\u1ebfn \u0111\u1ed5i th\u00e0nh h\u1ea1t nh\u00e2n kh\u00e1c.<\/p>\n

      – D\u1ea1ng c\u1ee7a ph\u01b0\u01a1ng tr\u00ecnh ph\u00f3ng x\u1ea1 \u03b2^{+<\/sup>\u00a0:\u00a0<\/p>\n}

      – Th\u1ef1c ch\u1ea5t c\u1ee7a ph\u00f3ng x\u1ea1\u00a0 \u03b2^{+<\/sup>\u00a0\u00a0l\u00e0 trong h\u1ea1t nh\u00e2n, 1 proton bi\u1ebfn \u0111\u1ed5i th\u00e0nh 1 notron, 1 e+\u00a0v\u00e0 1 notrino\u00a0<\/p>\n}

      – \u0110\u1eb7c \u0111i\u1ec3m c\u1ee7a tia \u00a0\u03b2^{+<\/sup>\u00a0:<\/p>\n}

      + L\u00e0 d\u00f2ng c\u00e1c pozitron chuy\u1ec3n \u0111\u1ed9ng v\u1edbi v\u1eadn t\u1ed1c g\u1ea7n b\u1eb1ng t\u1ed1c \u0111\u1ed9 \u00e1nh s\u00e1ng.<\/p>\n

      + L\u00e0m ion h\u00f3a y\u1ebfu h\u01a1n tia \u03b2^{–<\/sup>\u00a0nh\u01b0ng m\u1ea1nh h\u01a1n tia X.<\/p>\n}

      + B\u1ecb l\u1ec7ch v\u1ec1 b\u1ea3n \u00e2m c\u1ee7a t\u1ee5 \u0111i\u1ec7n.<\/p>\n

      + \u0110i \u0111\u01b0\u1ee3c kho\u1ea3ng v\u00e0i met trong kh\u00f4ng kh\u00ed, v\u00e0i milimet trong kim lo\u1ea1i.<\/p>\n

      2.4 Ph\u00f3ng x\u1ea1 Y:<\/p>\n

      – M\u1ed1t s\u1ed1 h\u1ea1t nh\u00e2n con sau qu\u00e1 tr\u00ecnh ph\u00f3ng x\u1ea1\u00a0\u221d\u00a0hay \u03b2^{+<\/sup>\u00a0,\u03b2–<\/sup>\u00a0\u0111\u01b0\u1ee3c t\u1ea1o ra trong tr\u1ea1ng th\u00e1i k\u00edch th\u00edch. Khi \u0111\u00f3 x\u1ea3y ra ti\u1ebfp qu\u00e1 tr\u00ecnh h\u1ea1t nh\u00e2n \u0111\u00f3 chuy\u1ec3n t\u1eeb tr\u1ea1ng th\u00e1i k\u00edch th\u00edch v\u1ec1 tr\u1ea1ng th\u00e1i c\u00f3 m\u1ee9c n\u0103ng l\u01b0\u1ee3ng th\u1ea5p h\u01a1n v\u00e0 ph\u00e1t ra b\u1ee9c x\u1ea1 \u0111i\u1ec7n t\u1eeb, c\u00f2n g\u1ecdi l\u00e0 tia Y.<\/p>\n}

      – \u0110\u1eb7c \u0111i\u1ec3m c\u1ee7a tia Y:<\/p>\n

      + L\u00e0 d\u00f2ng photon c\u00f3 n\u0103ng l\u01b0\u1ee3ng cao m\u00e0 m\u1eaft th\u01b0\u1eddng kh\u00f4ng nh\u00ecn th\u1ea5y \u0111\u01b0\u1ee3c, c\u00f3 b\u01b0\u1edbc s\u00f3ng ng\u1eafn h\u01a1n b\u01b0\u1edbc s\u00f3ng c\u1ee7a tia X.<\/p>\n

      + C\u00f3 \u0111\u1ea7y \u0111\u1ee7 c\u00e1c \u0111\u1eb7c \u0111i\u1ec3m c\u1ee7a tia X nh\u01b0ng c\u00f3 kh\u1ea3 n\u0103ng \u0111\u00e2m xuy\u00ean cao h\u01a1n, m\u1ea1nh h\u01a1n.<\/p>\n

      + L\u00e0m ion h\u00f3a kh\u00f4ng kh\u00ed k\u00e9m, tr\u00e1i l\u1ea1i kh\u1ea3 n\u0103ng \u0111\u00e2m xuy\u00ean l\u1ea1i r\u1ea5t m\u1ea1nh so v\u1edbi tia \u221d ,\u03b2\u00a0.<\/p>\n

      + C\u00f3 th\u1ec3 \u0111i \u0111\u01b0\u1ee3c v\u00e0i met trong b\u00ea t\u00f4ng, v\u00e0i cm trong ch\u00ec.<\/p>\n

      \n
      1. \u0110\u1ecbnh lu\u1eadt ph\u00f3ng x\u1ea1:<\/strong><\/li>\n<\/ol>\n

         3.1 \u0110\u1eb7c t\u00ednh c\u1ee7a qu\u00e1 tr\u00ecnh ph\u00f3ng x\u1ea1:<\/p>\n

         – C\u00f3 b\u1ea3n ch\u1ea5t l\u00e0 m\u1ed9t qu\u00e1 tr\u00ecnh bi\u1ebfn \u0111\u1ed5i h\u1ea1t nh\u00e2n.<\/p>\n

         – Ph\u00f3ng x\u1ea1 l\u00e0 m\u1ed9t qu\u00e1 tr\u00ecnh ph\u1ea3n \u1ee9ng h\u1ea1t nh\u00e2n t\u1ecfa n\u0103ng l\u01b0\u1ee3ng.<\/p>\n

         – C\u00f3 t\u00ednh t\u1ef1 ph\u00e1t v\u00e0 kh\u00f4ng \u0111i\u1ec1u khi\u1ec3n \u0111\u01b0\u1ee3c.<\/p>\n

         – L\u00e0 m\u1ed9t qu\u00e1 tr\u00ecnh ng\u1eabu nhi\u00ean.<\/p>\n

         3.2 \u0110\u1ecbnh lu\u1eadt ph\u00f3ng x\u1ea1:<\/p>\n

         Trong qu\u00e1 tr\u00ecnh ph\u00e2n r\u00e3, s\u1ed1 h\u1ea1t nh\u00e2n ph\u00f3ng x\u1ea1 gi\u1ea3m theo th\u1eddi gian theo quy lu\u1eadt h\u00e0m s\u1ed1 m\u0169.<\/p>\n

         <\/p>\n

         – N0\u00a0l\u00e0 s\u1ed1 nguy\u00ean t\u1eed ch\u1ea5t ph\u00f3ng x\u1ea1 l\u00fac t=0<\/p>\n

         – N l\u00e0 s\u1ed1 nguy\u00ean t\u1eed ch\u1ea5t ph\u00f3ng x\u1ea1 c\u00f2n l\u1ea1i l\u00fac t<\/p>\n

         – m0\u00a0l\u00e0 kh\u1ed1i l\u01b0\u1ee3ng ch\u1ea5t ph\u00f3ng x\u1ea1 l\u00fac t=0<\/p>\n

         – m l\u00e0 kh\u1ed1i l\u01b0\u1ee3ng\u00a0ch\u1ea5t ph\u00f3ng x\u1ea1 c\u00f2n l\u1ea1i l\u00fac t<\/p>\n

         – T l\u00e0 chu k\u1ef3 b\u00e1n r\u00e3 (c\u00f9ng \u0111\u01a1n v\u1ecb v\u1edbi t)<\/p>\n

         –\u00a0\u00a0l\u00e0 h\u1eb1ng s\u1ed1 ph\u00f3ng x\u1ea1.<\/p>\n

         3.3 Chu k\u1ef3 b\u00e1n r\u00e3:<\/p>\n

         – \u0110\u00f3 l\u00e0 th\u1eddi gian, qua \u0111\u00f3 s\u1ed1 l\u01b0\u1ee3ng c\u00e1c h\u1ea1t nh\u00e2n c\u00f2n l\u1ea1i 50%. K\u00fd hi\u1ec7u l\u00e0 T.<\/p>\n

         <\/p>\n

         \n
         1. \u0110\u1ed9 ph\u00f3ng x\u1ea1:<\/strong><\/li>\n<\/ol>\n

            – \u0110\u1ec3 \u0111\u1eb7c trung cho t\u00ednh ph\u00f3ng x\u1ea1 m\u1ea1nh hay y\u1ebfu c\u1ee7a m\u1ed9t l\u01b0\u1ee3ng ch\u1ea5t ph\u00f3ng x\u1ea1, ng\u01b0\u1eddi ta d\u00f9ng \u0111\u1ea1i l\u01b0\u1ee3ng g\u1ecdi l\u00e0 \u0111\u1ed9 ph\u00f3ng x\u1ea1, \u0111\u01b0\u1ee3c x\u00e1c \u0111\u1ecbnh b\u1eb1ng s\u1ed1 ph\u00e2n r\u00e3 trong m\u1ed9t gi\u00e2y.<\/p>\n

            <\/p>\n

            + \u0110\u1ec3 t\u00ednh H theo Bq th\u00ec\u00a0<\/p>\n

            + \u0110\u01a1n v\u1ecb \u0111o \u0111\u1ed9 ph\u00f3ng x\u1ea1 l\u00e0 becoren, k\u00fd hi\u1ec7u Bq.\u00a01 Bq= 1 ph\u00e2n r\u00e3\/s.<\/p>\n

            + Ngo\u00e0i ra ng\u01b0\u1eddi ta c\u00f2n d\u00f9ng 1 \u0111\u01a1n v\u1ecb kh\u00e1c c\u00f3 t\u00ean g\u1ecdi l\u00e0 Curi, k\u00ed hi\u1ec7u Ci<\/p>\n

            1 Ci = 3,7.1010 Bq, x\u1ea5p x\u1ec9 b\u1eb1ng \u0111\u1ed9 ph\u00f3ng x\u1ea1 c\u1ee7a 1 gam Radi.<\/p>\n

            => Nh\u01b0 v\u1eady \u0111\u1ed9 ph\u00f3ng x\u1ea1 c\u1ee7a m\u1ed9t l\u01b0\u1ee3ng ch\u1ea5t ph\u00f3ng x\u1ea1 gi\u1ea3m theo th\u1eddi gian theo c\u00f9ng quy lu\u1eadt h\u00e0m s\u1ed1 m\u0169 gi\u1ed1ng nh\u01b0 s\u1ed1 h\u1ea1t nh\u00e2n c\u1ee7a n\u00f3.<\/p>\n

            \n
            1. \u0110\u1ed3ng v\u1ecb ph\u00f3ng x\u1ea1 v\u00e0 \u1ee9ng d\u1ee5ng:<\/strong><\/li>\n<\/ol>\n

               5.1 \u0110\u1ed3ng v\u1ecb ph\u00f3ng x\u1ea1:<\/p>\n

               – V\u1eabn gi\u1ed1ng nh\u01b0 trong h\u00f3a h\u1ecdc, \u0111\u1ed3ng v\u1ecb l\u00e0 c\u00e1c h\u1ea1t nh\u00e2n c\u00f3 c\u00f9ng s\u1ed1 proton, kh\u00e1c nhau s\u1ed1 notron t\u1ee9c \u1edf c\u00f9ng m\u1ed9t v\u1ecb tr\u00ed trong b\u1ea3ng h\u1ec7 th\u1ed1ng tu\u1ea7n ho\u00e0n. Nh\u01b0ng kh\u00e1c \u1edf ch\u1ed7 l\u00e0 \u0111\u1ed3ng v\u1ecb ph\u00f3ng x\u1ea1 \u0111\u1ec1u l\u00e0 c\u00e1c h\u1ea1t nh\u00e2n kh\u00f4ng b\u1ec1n.<\/p>\n

               – C\u00f3 c\u1ea3 \u0111\u1ed3ng v\u1ecb ph\u00f3ng x\u1ea1\u00a0t\u1ef1 nhi\u00ean v\u00e0 \u0111\u1ed3ng v\u1ecb ph\u00f3ng x\u1ea1\u00a0nh\u00e2n t\u1ea1o.<\/p>\n

               – C\u00e1c \u0111\u1ed3ng v\u1ecb ph\u00f3ng x\u1ea1 c\u0169ng c\u00f3 t\u00ednh ch\u1ea5t h\u00f3a h\u1ecdc t\u01b0\u01a1ng t\u1ef1 nh\u01b0 \u0111\u1ed3ng v\u1ecb b\u1ec1n c\u1ee7a nguy\u00ean t\u1ed1 \u0111\u00f3.<\/p>\n

               5.2 \u1ee8ng d\u1ee5ng:<\/p>\n

               – Ph\u01b0\u01a1ng ph\u00e1p nguy\u00ean t\u1eed \u0111\u00e1nh d\u1ea5u:<\/p>\n

               – X\u00e1c \u0111\u1ecbnh tu\u1ed5i c\u1ee7a c\u1ed5 v\u1eadt d\u1ef1a theo ph\u00f3ng x\u1ea1\u00a0<\/p>\n

               II. C\u00e1c d\u1ea1ng b\u00e0i to\u00e1n v\u1ec1 ph\u00f3ng x\u1ea1 h\u1ea1t nh\u00e2n li\u00ean quan \u0111\u1ebfn hi\u1ec7n t\u01b0\u1ee3ng ph\u00f3ng x\u1ea1.<\/h3>\n

               \n
               1. X\u00e1c \u0111\u1ecbnh l\u01b0\u1ee3ng ch\u1ea5t ph\u00f3ng x\u1ea1 c\u00f2n l\u1ea1i ho\u1eb7c b\u1ecb ph\u00e2n r\u00e3:<\/strong><\/li>\n<\/ol>\n

                  – \u00c1p d\u1ee5ng c\u00f4ng th\u1ee9c:<\/p>\n

                  + S\u1ed1 h\u1ea1t nh\u00e2n ch\u1ea5t ph\u00f3ng x\u1ea1 c\u00f2n l\u1ea1i:\u00a0<\/p>\n

                  + Kh\u1ed1i l\u01b0\u1ee3ng ch\u1ea5t ph\u00f3ng x\u1ea1 c\u00f2n l\u1ea1i:<\/p>\n

                  \u00a0\u00a0\u00a0 <\/p>\n

                  + S\u1ed1 h\u1ea1t nh\u00e2n \u0111\u00e3 b\u1ecb ph\u00e2n r\u00e3:\u00a0<\/p>\n

                  + L\u01b0\u1ee3ng ch\u1ea5t ph\u00f3ng x\u1ea1 \u0111\u00e3 b\u1ecb ph\u00e2n r\u00e3:\u00a0<\/p>\n

                  + Kh\u1ed1i l\u01b0\u1ee3ng ch\u1ea5t m\u1edbi \u0111\u01b0\u1ee3c t\u1ea1o th\u00e0nh:<\/p>\n

                  <\/p>\n

                  (S\u1ed1 mol c\u1ee7a ch\u1ea5t ph\u00f3ng x\u1ea1 b\u1ecb ph\u00e2n r\u00e3 = s\u1ed1 mol ch\u1ea5t m\u1edbi t\u1ea1o th\u00e0nh)<\/p>\n

                  – Ghi ch\u00fa: M\u1ed1i li\u00ean h\u1ec7 gi\u1eefa m v\u00e0 N l\u00e0\u00a0<\/p>\n

                  + A l\u00e0 s\u1ed1 kh\u1ed1i<\/p>\n

                  + NA l\u00e0 s\u1ed1 Avogadro (6,02.1023\u00a0nguy\u00ean t\u1eed\/mol)<\/p>\n

                  \u00a0– V\u00ed d\u1ee5 1<\/strong> v\u1ec1 c\u00e1c d\u1ea1ng b\u00e0i to\u00e1n v\u1ec1 ph\u00f3ng x\u1ea1 h\u1ea1t nh\u00e2n:\u00a0Cho ch\u1ea5t ph\u00f3ng x\u1ea1\u00a0\u00a0ph\u00f3ng ra tia ph\u00f3ng x\u1ea1\u00a0\u221d\u00a0v\u00e0 bi\u1ebfn th\u00e0nh h\u1ea1t nh\u00e2n ch\u00ec \u00a0. Cho bi\u1ebft chu k\u1ef3 b\u00e1n r\u00e3 c\u1ee7a Po l\u00e0 138 ng\u00e0y \u0111\u00eam.<\/em><\/p>\n

                  a) Trong 0,168g Po c\u00f3 bao nhi\u00eau nguy\u00ean t\u1eed b\u1ecb ph\u00e2n r\u00e3 sau 414 ng\u00e0y \u0111\u00eam v\u00e0 x\u00e1c \u0111\u1ecbnh l\u01b0\u1ee3ng ch\u00ec \u0111\u01b0\u1ee3c t\u1ea1o th\u00e0nh trong kho\u1ea3ng th\u1eddi gian n\u00f3i tr\u00ean ?<\/em><\/p>\n

                  b) Sau bao nhi\u00eau l\u00e2u th\u00ec trong 0,168g ch\u1ec9 c\u00f2n l\u1ea1i 10,5 mg ?<\/em><\/p>\n

                  B\u00e0i gi\u1ea3i:<\/strong><\/p>\n

                  a)<\/p>\n

                  – S\u1ed1\u00a0nguy\u00ean t\u1eed Po b\u1ecb ph\u00e2n r\u00e3 sau 414 ng\u00e0y \u0111\u00eam:<\/p>\n

                  <\/p>\n

                  – Kh\u1ed1i l\u01b0\u1ee3ng ch\u00ec \u0111\u01b0\u1ee3c t\u1ea1o th\u00e0nh:<\/p>\n

                  <\/p>\n

                  b)<\/p>\n

                  <\/p>\n

                  2. X\u00e1c \u0111\u1ecbnh chu k\u1ef3 b\u00e1n r\u00e3 ho\u1eb7c h\u1eb1ng s\u1ed1 ph\u00f3ng x\u1ea1.<\/strong><\/p>\n

                  – \u00c1p d\u1ee5ng c\u00f4ng th\u1ee9c:<\/p>\n

                  + X\u00e1c \u0111\u1ecbnh h\u1eb1ng s\u1ed1 ph\u00f3ng x\u1ea1:\u00a0<\/p>\n

                  +\u00a0<\/p>\n

                  – V\u00ed d\u1ee5 2<\/strong> v\u1ec1 c\u00e1c d\u1ea1ng b\u00e0i to\u00e1n v\u1ec1 ph\u00f3ng x\u1ea1 h\u1ea1t nh\u00e2n:\u00a0Cho 0,2 mg\u00a0\u00a0ph\u00f3ng x\u1ea1 1,35.108\u00a0h\u1ea1t\u00a0\u00a01 ph\u00fat. H\u00e3y t\u00ecm chu k\u1ef3 b\u00e1n r\u00e3 c\u1ee7a Ra, cho bi\u1ebft chu k\u1ef3 n\u00e0y r\u1ea5t l\u1edbn so v\u1edbi kho\u1ea3ng th\u1eddi gian quan s\u00e1t.<\/em><\/p>\n

                  B\u00e0i gi\u1ea3i:\u00a0<\/em><\/p>\n

                  <\/p>\n

                  \n
                  1. X\u00e1c \u0111\u1ecbnh \u0111\u1ed9 ph\u00f3ng x\u1ea1 v\u00e0 tu\u1ed5i c\u1ee7a m\u1eabu v\u1eadt.<\/strong><\/li>\n<\/ol>\n

                     3.1 X\u00e1c \u0111\u1ecbnh \u0111\u1ed9 ph\u00f3ng x\u1ea1:<\/p>\n

                     – \u00c1p d\u1ee5ng c\u00f4ng th\u1ee9c:<\/p>\n

                     + X\u00e1c \u0111\u1ecbnh \u0111\u1ed9 ph\u00f3ng x\u1ea1:\u00a0<\/p>\n

                     + L\u01b0u \u00fd:\u00a0<\/p>\n

                     B\u00e0i t\u1eadp v\u00ed d\u1ee5 v\u1ec1 c\u00e1c d\u1ea1ng b\u00e0i to\u00e1n v\u1ec1 ph\u00f3ng x\u1ea1 h\u1ea1t nh\u00e2n:\u00a0V\u00e0o \u0111\u1ea7u n\u0103m 1985, m\u1ed9t ph\u00f2ng th\u00ed nghi\u1ec7m nh\u1eadn \u0111\u01b0\u1ee3c m\u1eabu qu\u1eb7ng c\u00f3 ch\u1ee9a ch\u1ea5t ph\u00f3ng x\u1ea1, m\u1eabu qu\u1eb7ng\u00a0. Khi \u0111\u00f3 \u0111\u1ed9 ph\u00f3ng x\u1ea1 c\u1ee7a ch\u1ea5t n\u00e0y H0=1,8.105\u00a0Bq.<\/em><\/p>\n

                     a) T\u00ednh kh\u1ed1i l\u01b0\u1ee3ng c\u1ee7a Cs ch\u1ee9a trong m\u1eabu qu\u1eb7ng \u0111\u00f3, cho bi\u1ebft chu k\u1ef3 b\u00e1n r\u00e3 c\u1ee7a Cs l\u00e0 30 n\u0103m.<\/em><\/p>\n

                     b) T\u00ecm \u0111\u1ed9 ph\u00f3ng x\u1ea1 c\u1ee7a m\u1eabu qu\u1eb7ng \u0111\u00f3 v\u00e0o \u0111\u1ea7u n\u0103m 1995.<\/em><\/p>\n

                     B\u00e0i gi\u1ea3i:<\/em><\/p>\n

                     a)\u00a0<\/p>\n

                     b)\u00a0<\/p>\n

                     3.2 X\u00e1c \u0111\u1ecbnh tu\u1ed5i c\u1ee7a m\u1eabu v\u1eadt.<\/p>\n

                     – X\u00e1c \u0111\u1ecbnh tu\u1ed5i c\u1ee7a m\u1eabu th\u1ef1c v\u1eadt:<\/p>\n

                     + Khi th\u1ef1c v\u1eadt s\u1ed1ng th\u00ec h\u00e0m l\u01b0\u1ee3ng\u00a0\u00a0kh\u00f4ng \u0111\u1ed5i do lu\u00f4n \u0111\u01b0\u1ee3c b\u00f9 \u0111\u1eafp ph\u1ea7n m\u1ea5t \u0111i.<\/p>\n

                     + T\u1eeb khi c\u00e2y ch\u1ebft th\u00ec h\u00e0m l\u01b0\u1ee3ng gi\u1ea3m\u00a0\u00a0n\u00ean \u0111\u1ed9 ph\u00f3ng x\u1ea1 c\u0169ng gi\u1ea3m theo.<\/p>\n

                     <\/p>\n

                     – X\u00e1c \u0111\u1ecbnh tu\u1ed5i c\u1ee7a m\u1eabu kho\u00e1ng ch\u1ea5t:<\/p>\n

                     + S\u1ed1 h\u1ea1t nh\u00e2n X m\u1ea5t \u0111i = S\u1ed1 h\u1ea1t nh\u00e2n X’ t\u1ea1o th\u00e0nh<\/p>\n

                     <\/p>\n

                     * V\u00ed d\u1ee5 v\u1ec1 c\u00e1c d\u1ea1ng b\u00e0i to\u00e1n v\u1ec1 ph\u00f3ng x\u1ea1 h\u1ea1t nh\u00e2n:\u00a0T\u00ednh tu\u1ed5i c\u1ee7a m\u1ed9t t\u01b0\u1ee3ng c\u1ed5 b\u1eb1ng g\u1ed7, bi\u1ebft r\u1eb1ng \u0111\u1ed9 ph\u00f3ng x\u1ea1 c\u1ee7a n\u00f3 b\u1eb1ng 77% \u0111\u1ed9 ph\u00f3ng x\u1ea1 ban \u0111\u1ea7u c\u1ee7a m\u1ed9t kh\u00fac g\u1ed7 c\u00f3 c\u00f9ng kh\u1ed1i l\u01b0\u1ee3ng v\u1eeba m\u1edbi ch\u1eb7t, chu k\u1ef3 b\u00e1n r\u00e3 c\u1ee7a\u00a014C l\u00e0 5600 n\u0103m ?<\/em><\/p>\n

                     B\u00e0i gi\u1ea3i:<\/em><\/p>\n

                     <\/p>\n

                     * V\u00ed d\u1ee5 v\u1ec1 c\u00e1c d\u1ea1ng b\u00e0i to\u00e1n v\u1ec1 ph\u00f3ng x\u1ea1 h\u1ea1t nh\u00e2n\u00a0:\u00a0Khi ph\u00e2n t\u00edch m\u1ed9t m\u1eabu g\u1ed7 c\u1ed5 ng\u01b0\u1eddi ta th\u1ea5y 87,5% s\u1ed1 nguy\u00ean t\u1eed \u0111\u1ed3ng v\u1ecb cacbon\u00a0\u00a0\u0111\u00e3 b\u1ecb ph\u00e2n r\u00e3 th\u00e0nh c\u00e1c nguy\u00ean t\u1eed \u00a0. Cho bi\u1ebft chu k\u1ef3 b\u00e1n r\u00e3 c\u1ee7a\u00a0\u00a0l\u00e0 5570 n\u0103m. H\u1ecfi tu\u1ed5i c\u1ee7a m\u1eabu g\u1ed7 c\u1ed5 n\u00e0y l\u00e0 bao nhi\u00eau ?<\/em><\/p>\n

                     B\u00e0i gi\u1ea3i:<\/em><\/p>\n

                     <\/p>\n","protected":false},"excerpt":{"rendered":"

                     \u00a0Ph\u00f3ng x\u1ea1 l\u00e0 m\u1ed9t d\u1ea1ng to\u00e1n d\u1ec5 trong ch\u01b0\u01a1ng tr\u00ecnh v\u1eadt l\u00fd h\u1ea1t nh\u00e2n v\u00e0 d\u1ec5 \u0103n \u0111i\u1ec3m t\u1ed1i \u0111a trong c\u00e1c \u0111\u1ec1 thi ch\u1ec9 c\u1ea7n b\u1ea1n n\u1eafm ch\u1eafc l\u00fd… <\/p>\n","protected":false},"author":9,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[450,470],"tags":[],"amp_enabled":true,"_links":{"self":[{"href":"https:\/\/onthitot.com\/wp-json\/wp\/v2\/posts\/10994"}],"collection":[{"href":"https:\/\/onthitot.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/onthitot.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/onthitot.com\/wp-json\/wp\/v2\/users\/9"}],"replies":[{"embeddable":true,"href":"https:\/\/onthitot.com\/wp-json\/wp\/v2\/comments?post=10994"}],"version-history":[{"count":0,"href":"https:\/\/onthitot.com\/wp-json\/wp\/v2\/posts\/10994\/revisions"}],"wp:attachment":[{"href":"https:\/\/onthitot.com\/wp-json\/wp\/v2\/media?parent=10994"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/onthitot.com\/wp-json\/wp\/v2\/categories?post=10994"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/onthitot.com\/wp-json\/wp\/v2\/tags?post=10994"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}