Question Detail
Question
The missing product from this reaction ¹²¹₅₃I → ¹²¹₅₂Pb + ______ is
Correct Answer
Option A is the correct answer.
Detailed Explanation
The mass number on both sides must balance: 121 = 121 + A => A = 0. The atomic number: 53 = 52 + Z => Z = 1. The particle with mass number 0 and atomic number -1 is a beta particle (electron): ⁰₋₁e. Option A is ⁰₋₁e. Option D is a positron (⁰₊₁e).
Hint
Balance the mass number (A) and atomic number (Z) on both sides of the equation.