Balancing Nuclear Equations ✏ Chemistry In a Nutshell

Rucete ✏ Chemistry In a Nutshell

1. Steps to Balance a Nuclear Equation

To correctly balance a nuclear equation, follow these steps:

1. Identify the type of decay (α, β, γ) and emitted particle.
2. Determine the daughter nucleus:
   • Find mass number (A) and atomic number (Z) of the resulting nucleus.
3. Ensure mass number (A) and atomic number (Z) are conserved:
   • Sum of mass numbers (A) must be equal on both sides.
   • Sum of atomic numbers (Z) must be equal on both sides.
4. Use the periodic table to identify the new element.

2. Example: Thorium-232 (²³²₉₀Th) Undergoing Alpha (α) Decay

$${}_{90}^{232}Th\to {}_{88}^{228}Ra+{}_2^{4}He$$

• Explanation:
• Thorium (Th) loses an alpha particle (⁴₂He).
• Mass number decreases by 4 (232 → 228).
• Atomic number decreases by 2 (90 → 88).
• Using the periodic table, Z = 88 corresponds to Radium (Ra).

3. General Balancing Rules

Decay Type	Change in Mass Number (A)	Change in Atomic Number (Z)
Alpha (α) Decay (⁴₂He)	A decreases by 4	Z decreases by 2
Beta (β⁻) Decay (⁰₋₁e)	A remains the same	Z increases by 1
Positron (β⁺) Emission (⁰₁e)	A remains the same	Z decreases by 1
Electron Capture (EC)	A remains the same	Z decreases by 1
Gamma (γ) Decay	No change in A or Z	No change

In a nutshell

• Mass (A) and Atomic Number (Z) must balance on both sides.
• Use periodic table to find the new element.
• Different decays affect A and Z differently.