Beta-+ Decay Nuclear Reaction Example Problem

This example problem demonstrates how to write a nuclear reaction process involving β⁺ decay.

Problem:

An atom of ²²Na₁₁ undergoes β⁺ decay and produces a positron.

Write a chemical equation showing this reaction.

Solution:

Nuclear reactions need to have the sum of protons and neutrons the same on both sides of the equation. The number of protons must also be consistent on both sides of the reaction.

β⁺ decay occurs when a proton converts into a neutron and ejects an energetic positively charged electron, or positron. This means the the number of neutrons, N, is increased by 1 and the number of protons, A, is decreased by 1 on the daughter atom.

²²Na₁₁ → ^ZX_A + ⁰e₊₁

A = number of protons = 11 - 1 = 10

X = the element with atomic number = 10

According to the periodic table, X = Neon or Ne.

The mass number, A, remains unchanged because the loss of one proton is offset by the addition of a neutron.

Z = 22

Substitute these values into the reaction:

²²Na₁₁ → ²²Ne₁₀ + ⁰e₊₁