Electrons exist in specific, quantized main energy levels (n). They cannot exist between levels.
Key Principles
- 1 Energy Increases with n: n=1 is closest to the nucleus (Ground State) and has the lowest energy. High n = High Energy.
- 2 Convergence: As n increases, the energy gaps between shells get smaller. The levels "converge" at \(n = \infty \).
Maximum Electrons per Shell
\(2n^2\)
Shell n=1
2
Shell n=2
8
Shell n=3
18
Shell n=4
32
Why do shells converge?
The attraction from the nucleus drops off with distance (Inverse Square Law). At higher energy levels (further away), the difference in attraction between step n and step n+1 becomes negligible, so the energy difference (\(\Delta E\)) becomes tiny.