Hướng dẫn giải Bài 7 (Trang 187 SGK Vật lý 12)

Hoàn chỉnh các phản ứng a) <math xmlns="http://www.w3.org/1998/Math/MathML"><mmultiscripts><mi>L</mi><mprescripts/><mn>3</mn><mn>6</mn></mmultiscripts><mi>i</mi><mo> </mo><mo>+</mo><mo> </mo><mmultiscripts><mi>X</mi><mprescripts/><mi>Z</mi><mi>A</mi></mmultiscripts><mo> </mo><mo>→</mo><mmultiscripts><mi>B</mi><mprescripts/><mn>4</mn><mn>7</mn></mmultiscripts><mi>e</mi><mo> </mo><mo>+</mo><mo> </mo><mmultiscripts><mi>n</mi><mprescripts/><mn>0</mn><mn>1</mn></mmultiscripts></math> Áp dụng định luật bảo toàn diện tích và bảo toàn số nuclôn 3 + Z = 4 + 0 <math xmlns="http://www.w3.org/1998/Math/MathML"><mo>⇒</mo></math>Z = 1 6 + A = 7 + 1 <math xmlns="http://www.w3.org/1998/Math/MathML"><mo>⇒</mo></math> A = 2 Vậy <math xmlns="http://www.w3.org/1998/Math/MathML"><mmultiscripts><mi>X</mi><mprescripts/><mi>Z</mi><mi>A</mi></mmultiscripts><mo> </mo><mo>=</mo><mo> </mo><mmultiscripts><mi>H</mi><mprescripts/><mn>1</mn><mn>2</mn></mmultiscripts><mo> </mo><mo>=</mo><mo> </mo><mmultiscripts><mi>D</mi><mprescripts/><mn>1</mn><mn>2</mn></mmultiscripts></math> <math xmlns="http://www.w3.org/1998/Math/MathML"><mmultiscripts><mi>L</mi><mprescripts/><mn>3</mn><mn>6</mn></mmultiscripts><mi>i</mi><mo> </mo><mo>+</mo><mo> </mo><mmultiscripts><mi>D</mi><mprescripts/><mn>1</mn><mn>2</mn></mmultiscripts><mo> </mo><mo>→</mo><mo> </mo><mmultiscripts><mi>B</mi><mprescripts/><mn>4</mn><mn>7</mn></mmultiscripts><mi>e</mi><mo> </mo><mo>+</mo><mo> </mo><mmultiscripts><mi>n</mi><mprescripts/><mn>0</mn><mn>1</mn></mmultiscripts></math> b) <math xmlns="http://www.w3.org/1998/Math/MathML"><mmultiscripts><mi>B</mi><mprescripts/><mn>5</mn><mn>10</mn></mmultiscripts><mo> </mo><mo>+</mo><mo> </mo><mmultiscripts><mi>X</mi><mprescripts/><mi>Z</mi><mi>A</mi></mmultiscripts><mo> </mo><mo>→</mo><mo> </mo><mmultiscripts><mi>L</mi><mprescripts/><mn>3</mn><mn>7</mn></mmultiscripts><mi>i</mi><mo> </mo><mo>+</mo><mo> </mo><mmultiscripts><mi>H</mi><mprescripts/><mn>2</mn><mn>4</mn></mmultiscripts><mi>e</mi></math> Áp dụng định luật bảo toàn diện tích và bảo toàn số nuclôn  5 + Z = 3 + 2 <math xmlns="http://www.w3.org/1998/Math/MathML"><mo>⇒</mo></math> Z = 0 10 + A = 7 + 4 <math xmlns="http://www.w3.org/1998/Math/MathML"><mo>⇒</mo></math>A = 1 Vậy <math xmlns="http://www.w3.org/1998/Math/MathML"><mmultiscripts><mi>X</mi><mprescripts/><mi>Z</mi><mi>A</mi></mmultiscripts><mo> </mo><mo>=</mo><mo> </mo><mmultiscripts><mi>n</mi><mprescripts/><mn>0</mn><mn>1</mn></mmultiscripts></math> <math xmlns="http://www.w3.org/1998/Math/MathML"><mmultiscripts><mi>B</mi><mprescripts/><mn>5</mn><mn>10</mn></mmultiscripts><mo> </mo><mo>+</mo><mo> </mo><mmultiscripts><mi>n</mi><mprescripts/><mn>0</mn><mn>1</mn></mmultiscripts><mo> </mo><mo>→</mo><mmultiscripts><mi>L</mi><mprescripts/><mn>3</mn><mn>7</mn></mmultiscripts><mi>i</mi><mo> </mo><mo>+</mo><mo> </mo><mmultiscripts><mi>H</mi><mprescripts/><mn>2</mn><mn>4</mn></mmultiscripts><mi>e</mi></math> c) Tương tự:    <math xmlns="http://www.w3.org/1998/Math/MathML"><mmultiscripts><mi>C</mi><mprescripts/><mn>17</mn><mn>35</mn></mmultiscripts><mi>l</mi><mo> </mo><mo>+</mo><mo> </mo><mmultiscripts><mi>X</mi><mprescripts/><mi>Z</mi><mi>A</mi></mmultiscripts><mo> </mo><mo>→</mo><mmultiscripts><mi>S</mi><mprescripts/><mn>16</mn><mn>32</mn></mmultiscripts><mo> </mo><mo>+</mo><mo> </mo><mmultiscripts><mi>H</mi><mprescripts/><mn>2</mn><mn>4</mn></mmultiscripts><mi>e</mi></math>                     <math xmlns="http://www.w3.org/1998/Math/MathML"><mo>⇒</mo><mmultiscripts><mi>C</mi><mprescripts/><mn>17</mn><mn>35</mn></mmultiscripts><mi>l</mi><mo> </mo><mo>+</mo><mo> </mo><mmultiscripts><mi>H</mi><mprescripts/><mn>1</mn><mn>1</mn></mmultiscripts><mo> </mo><mo>→</mo><mmultiscripts><mi>S</mi><mprescripts/><mn>16</mn><mn>32</mn></mmultiscripts><mo> </mo><mo>+</mo><mo> </mo><mmultiscripts><mi>H</mi><mprescripts/><mn>2</mn><mn>4</mn></mmultiscripts><mi>e</mi></math>