The nucleus is stable.
Work Step by Step
The protons in the nucleus repel one another electrically, while the neutrons have no electrical force on them. The gravitational attraction between elementary particles is much, much weaker than the electrical forces, as shown in Example 21.1. The nucleus doesn’t blow itself apart, so there must be some other force holding the protons and neutrons together. This fundamental, short-range interaction is known as the strong force.