Q. 5.43 - An Introduction to General, Organic, and Biological Chemistry

Question

Complete the following fission reaction.

${}_0{}^{1}n + {}_{92}{}^{235}U \to {}_{50}{}^{131}Sn + ? +2 {}_0{}^{1}n + Energy$

Step-by-Step Solution

Answer

The fission reaction is ${}_{92}{}^{235}U + {}_0{}^{1}n \to {}_{50}{}^{131}Sn + {}_{42}{}^{105}Mo+2 {}_0{}^{1}n + Energy$.

Step 1: Introduction

Create a fission reaction that is incomplete.

${}_{92}{}^{235}U + {}_0{}^{1}n \to {}_{50}{}^{131}Sn + ? +2 {}_0{}^{1}n + Energy$

Step 2 Determine the mass number that is missing.

$235+1=131+?+2$

$236=133+?$

$236=131+?$

$105=?$(number of new nuclei in mass)

Step 2: Explanation

Determine the atomic number that is missing.

$92+0=50+?+0$

$92-50=?$

$42=?$(new nucleus' atomic number)

Step 4 Determine the new nucleus's symbol - the element with atomic number $42$ on the periodic table is molybdenum, $Mo$; the symbol for this isotope of $Mo$ is written as${}_{42}{}^{105}Mo$

Step 5 Bring the fission reaction to a conclusion.

${}_{92}{}^{235}U + {}_0{}^{1}n \to {}_{50}{}^{131}Sn + {}_{42}{}^{105}Mo+2 {}_0{}^{1}n + Energy$