Atomic shells
Electron shells are a useful first map of occupied energy levels, but not a literal picture of electron paths.
Read the picture
The illustration is conceptual. It shows relationships, not a literal photograph of atoms, orbitals or microscopic particles.
MendeleevUse the picture to make a prediction first. Then open the deeper science page and see where the simple model works—and where it stops working.
Core Wëssenschaft →
How to use this page
Start by identifying the quantity, element or phenomenon being studied, then connect it with a concrete situation. A scientific formula becomes much easier to understand once every term and unit has a clear physical meaning.
Mendeleev’s habit: always check the order of magnitude. A calculation can look correct while giving a physically impossible result when a unit has been forgotten or converted incorrectly.