Electron shell

An electron shell is a grouping of electrons within an atom that have similar energy levels and are located at a certain distance from the nucleus. These shells are defined by quantum mechanics and are an important aspect of atomic structure. ### Key Points about Electron Shells: 1. **Energy Levels**: Electrons are arranged in shells around the nucleus, each with a specific energy level. The shells are designated by principal quantum numbers (n = 1, 2, 3, etc.