Why must heavy stable nucleus contain more neutrons than protons ?

Explanation

To understand why heavy stable nuclei contain more neutrons than protons, we can break down the explanation into several steps:

### Step-by-Step Solution:

1. **Understanding Nuclear Forces**:
- In a nucleus, there are two types of forces at play: the nuclear force and the Coulomb force. The nuclear force is an attractive force that acts between all nucleons (neutrons and protons), while the Coulomb force is a repulsive force that acts between protons due to their positive charge.

2. **Role of Protons**:
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