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

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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 O2-

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