ELECTRON CONFIGURATION HOTEL CHEMISTRY • Welcome to the electron hotel ……what a lovely place! • Imagine you are the owner of a hotel. • Rooms are filled up in a certain order. • You want to fill the rooms on the lower floors first. • Each room can only hold a certain number of people. • Each room can only hold 2 people! • Some rooms fill faster than others. • Each person in a hotel can be found using their floor, room, and bed number. • THIS IS JUST LIKE THE ELECTRONS AND THEIR ORBITALS! ELECTRON HOTEL QUANTUM MECHANICAL MODEL • Describes electrons behaving as waves. • The exact location of the electron is determined by Schrödinger’s wave equation. • Describes the probable location of the electrons as a location in an orbital. • The electron can be described using four quantum numbers. ATOMIC ORBITAL • Principal quantum number ( n) • Principal energy level • n = 1-7 • Relative size and energy of atomic orbitals • As n increases, the electron is further from nucleus, and atom’s energy level increases • Angular quantum number ( lll) • Describes the shape of the orbital • (s, p, d, f) • l = 0 to n-1 • Magnetic quantum number (m lll) • x, y, z • mlll = ---l to + lll • Electron spin quantum number (ms) • ↑ (up) • ↓ (down) • ms = +½ or -½ ORBITAL SUBLEVELS • s, p, d, f • s orbital can hold 2 electrons • p orbitals (3) can hold a total of 6 electrons • d orbitals (5) can hold a total of 10 electrons • f orbitals (7) can hold a total of 14 electrons AUFBAU PRINCIPLE • Aufbau Principle – Each electron occupies the lowest energy orbital available. • Aufbau Diagram • Each box represents an atomic orbital PAULI EXCLUSION PRINCIPLE • Pauli Exclusion Principle – a maximum of two electrons can occupy a single atomic orbital, but only if the electrons have opposite spins. HUND’S RULE • Hund’s Rule – single electrons with the same spin must occupy each equal-energy orbital before additional electrons with opposite spins can occupy the same orbitals ELECTRON ARRANGEMENT • Two methods: • Orbital Diagrams • Electron Configuration # of electrons • Orbital Diagrams • Aufbau Diagrams 1 Energy level 1s • Electron Configuration • 1s 1 Sub-level (Orbital) ELECTRON CONFIGURATION & ORBITAL DIAGRAM ELECTRON CONFIGURATION & ORBITAL DIAGRAM • Energy level 1 = s orbital • Energy level 2 = s, p orbital • Energy level 3 = s, p, d orbital • Energy level 4 = s, p, d, f orbital • Energy level 5 = s, p, d, f orbital • Energy level 6 = s, p, d orbital • Energy level 7 = s, p orbital PRINCIPLE QUANTUM NUMBER # ORBITALS IN SUBLEVEL MAX # e- (row or distance from SUBLEVEL nucleus) Size and energy 1 s 1 2 2 s p 1 3 8 3 s p d 1 3 5 18 4 s p d f 1 3 5 7 32 5 s p d f 1 3 5 7 32 6 s p d 1 3 5 18 7 S p 1 3 8 FILLING THE ORBITAL 1s 2s 2p 3s 3p 3d 4s 4p 4d 4f 5s 5p 5d 5f 6s 6p 6d 7s 7p.