Filling Electron Orbitals  Orbitals are the area in space where electrons are found  Each individual orbital holds 2 electrons  There are four main shapes which hold a different number of electrons

Shapes of Orbitals  The four shapes are s, p, d, and f

Shapes of the Orbitals  Each shape holds a different number of orbitals  s has 1 orbital, p has 3 orbitals, and d has 5 orbitals 

Energy Levels  Each period is a new energy level  Like an elevator, electrons cannot exist between energy levels!

General Rules  Aufbau Principle – Electrons fill lowest energy level first  Analogy: Lazy Tenant Rule

General Rules  Pauli Exclusion Principle – Electrons must have opposite spin (up/down) when in the same orbital  Analogy: Yin and Yang Rule

General Rules  Hund’s Rule – Electrons in equal energy orbits fill orbitals with parallel spin  Analogy: Empty Bus Seat Rule

Orbital Notation  Specific order for filling electrons – based on periodic table  Examples  Beryllium  Oxygen

Orbital Notation  Examples  O 2-  Titanium

Electron Configuration  Examples  Silicon  Selenium  Manganese

Shorthand Electron Config  Shorter version of writing electron configurations  Noble Gas Core – inner core of electrons not involved in chemical bonding