How the ideas connect
A good science page should make the connection visible, not just list definitions.
Aufbau principle
This concept connects electron structure with the architecture and chemical trends of the periodic table.
Mendeleev.com · scientific information checked against primary reference sources.
Electron configuration
Electron configuration describes how electrons occupy available atomic states. This arrangement is central to periodic trends and helps explain why elements in the same group often react in related ways.
The outer electrons are especially useful when you want to anticipate chemical behaviour.
Electron-configuration exceptions
This concept connects electron structure with the architecture and chemical trends of the periodic table.
Mendeleev.com · scientific information checked against primary reference sources.
Valence electrons
Valence electrons are the electrons most directly involved in bonding and chemical reactivity, although the exact boundary between valence and core can depend on context.
For main-group elements they provide a simple route to periodic similarities; transition metals require more care.
What to notice
A good science page should make the connection visible, not just list definitions.
Sources
IUPAC Gold Book · NIST · BIPM